IEEE Consumer Electronics Magazine - July 2017 - 107

period. This is not an accurate reflection of real-world software
development, as the second expert's own code shows, but nonetheless this is what the jury was told. This is just one of several
examples of the subjective nature of the criticisms of Toyota's
software quality presented to the jury by both experts. Other
examples can be found in my follow-up paper [27] to my IEEE
Technology and Society Magazine article [24] on this subject.

CAUSATION NOT DEMONSTRATED
The jury was told that "to a reasonable degree of engineering
certainty, it was more likely than not" that Task X death
caused the accident. Two theories were presented to support
this conclusion, but neither theory was credible. Nonetheless,
the jury accepted the conclusion.
The message provided to the jury by the plaintiffs was twofold:
▼ The defendant's software was poorly designed and full of
bugs.
▼ These bugs likely caused the accident.
As with all nontrivial software, there likely were bugs in the
defendant's software. Perhaps the plaintiffs found some of
them. But this does not mean that the accident was caused by
any of the purported bugs. Causation was not demonstrated.
Due to the nature of software, it seems likely that this same
scenario will play out in future embedded software trials. A key
to ensuring that an informed decision will be reached by the jury
in such a trial is for both plaintiffs and defendants to adequately
address the second bullet point above, causation. Otherwise, the
jury can be convinced that causation has been demonstrated
when in fact all that has occurred is that the quality of the defendant's software has been criticized, perhaps legitimately and perhaps not. This appears to be what happened in this trial.

ACKNOWLEDGMENT
This is a modified version of an article appearing in the
December 2016 issue of IEEE Technology and Society Magazine [24]. In the present article, references were made to the
full analysis from the original IEEE Technology and Society
Magazine article where appropriate.

ABOUT THE AUTHOR
David M. Cummings (dcummings@kellytechnologygroup
.com) earned his B.S. degree from Harvard University, Cambridge, Massachusetts, and his M.S. and Ph.D. degrees from the
University of California, Los Angeles. He is the executive vice
president of the Kelly Technology Group in Santa Barbara, California. He has more than 35 years of experience in the design
and implementation of software systems, many of which are
embedded systems. Nine of those years were spent at NASA's
Jet Propulsion Laboratory, where he designed and implemented
flight software for the Mars Pathfinder spacecraft.

REFERENCES
[1] Legal Information Institute. Burden of proof. Cornell University Law
School. [Online]. Available: https://www.law.cornell.edu/wex/burden_of_
proof
[2] Legal Information Institute. Preponderance. Cornell University Law
School. [Online]. Available: https://www.law.cornell.edu/wex/preponderance

[3] Justia. Evidentiary standards and burdens of proof. [Online]. Available: https://www.justia.com/trials-litigation/evidentiary-standardsburdens-proof/
[4] Nolo. Legal standards of proof. [Online]. Available: http://www.nolo
.com/legal-encyclopedia/legal-standards-proof.html
[5] Justia. Actual and proximate cause. [Online]. Available: https://www
.justia.com/injury/negligence-theory/actual-and-proximate-cause/
[6] Legal Information Institute. Actual cause. Cornell University Law
School. [Online]. Available: https://www.law.cornell.edu/wex/actual_cause
[7] Legal Information Institute. But-for test. Cornell University Law
School. [Online]. Available: https://www.law.cornell.edu/wex/but-for_test
[8] Legal Information Institute. Proximate cause. Cornell University Law
School. [Online]. Available: https://www.law.cornell.edu/wex/proximate_cause
[9] Thomson Reuters. Elements of a negligence case. FindLaw. [Online].
Available: http://images.findlaw.com/optimost/accident-injury-law/
elements-of-a-negligence-case-2.html
[10] Liability. Law.com. [Online]. Available: http://dictionary.law.com/
Default.aspx?selected=1151
[11] Proximate cause. Law.com. [Online]. Available: http://dictionary
.law.com/Default.aspx?selected=1669
[12] Proximate cause. The Free Dictionary. [Online]. Available: http://
legal-dictionary.thefreedictionary.com/proximate+cause
[13] N. Leveson. (2011). White paper on the use of safety cases in certification and regulation. [Online]. p. 6. Available: http://sunnyday.mit.edu/
SafetyCases.pdf
[14] D. Pogue. (2014, Nov. 1). 5 most embarrassing software bugs in history. Scientific American. [Online]. Available: http://www.scientificamerican
.com/article/pogue-5-most-embarrassing-software-bugs-in-history/
[15] C. Metz. (2004, Aug. 3). Is Microsoft to blame? PC Mag. [Online].
Available: http://www.pcmag.com/article2/0,2817,1618393,00.asp
[16] IEEE. IEEE code of ethics, #3 and #9. [Online]. Available: http://
www.ieee.org/about/corporate/governance/p7-8.html
[17] Association for Computing Machinery. Software engineering code
of ethics and professional practice, #1.06 and #4.03. [Online]. Available:
http://www.acm.org/about/se-code
[18] M. Barr. (2013, Oct. 26). An update on Toyota and unintended acceleration. Embedded Gurus. [Online]. Available: http://embeddedgurus.com/
barr-code/2013/10/an-update-on-toyota-and-unintended-acceleration/
[19] D. Cummings. (2010, Mar. 11). Haven't found that software glitch,
Toyota? Keep trying. Los Angeles Times. [Online]. Available: http://
www.latimes.com/news/opinion/opinionla/la-oew-cummings122010mar12,0,2595172.story
[20] National Highway Traffic Safety Administration. (2015, May 1).
Denial of motor vehicle defect petition. [Online]. pp. 11-15. Available:
http://www.safetyresearch.net/Library/INFD-DP14003-61928.pdf
[21] Bookout et al. v. Toyota. (2013, Oct. 11). Transcript of morning trial
proceedings. [Online]. Available: http://www.safetyresearch.net/Library/
Koopman%2010-11-13%20a.m.PDF
[22] Bookout et al. v. Toyota. (2013, Oct. 11). Transcript of afternoon
trial proceedings. [Online]. Available: http://www.safetyresearch.net/
Library/Koopman%2010-11-13%20p.m.pdf
[23] P. Koopman. (2014, Sept. 14). A case study of Toyota unintended
acceleration and software safety. [Online]. Available: https://users.ece
.cmu.edu/~koopman/pubs/koopman14_toyota_ua_slides.pdf
[24] D. M. Cummings, "Embedded software under the courtroom microscope," IEEE Technol. Soc. Mag., vol. 35, no. 4, pp. 76-84, Dec. 2016.
doi: 10.1109/MTS.2016.2618681.
[25] Bookout et al. v. Toyota. (2013, Oct. 14). Transcript of morning trial
proceedings. [Online]. Available: http://www.safetyresearch.net/Library/
Bookout_v_Toyota_Barr_REDACTED.pdf
[26] M. Barr. Bookout v. Toyota: 2005 Camry L4 software analysis.
[Online]. Available: http://www.safetyresearch.net/Library/BarrSlides_
FINAL_SCRUBBED.pdf
[27] D. M. Cummings. (2016, Dec. 5). Embedded software under the
Courtroom microscope, part 2-On the subjectivity of software quality
assessments. [Online]. Available: http://www.kellytechnologygroup.com/
main/DCummings_SW-Quality-Subjectivity.pdf

JULY 2017

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https://www.justia.com/trials-litigation/evidentiary-standards http://www.nolo https://www http://www.justia.com/injury/negligence-theory/actual-and-proximate-cause/ https://www.law.cornell.edu/wex/actual_cause https://www.law.cornell.edu/wex/but-for_test https://www.law.cornell.edu/wex/proximate_cause http://images.findlaw.com/optimost/accident-injury-law/ http://www.Law.com http://dictionary.law.com/ http://www.Law.com http://dictionary http://www.law.com/Default.aspx?selected=1669 http://http:// http://sunnyday.mit.edu/ http://www.scientificamerican http://www.pcmag.com/article2/0,2817,1618393,00.asp http://http:// http://www.ieee.org/about/corporate/governance/p7-8.html http://www.acm.org/about/se-code http://www.embeddedgurus.com/ http://http:// http://www.latimes.com/news/opinion/opinionla/la-oew-cummings12 http://www.safetyresearch.net/Library/INFD-DP14003-61928.pdf http://www.safetyresearch.net/Library/ http://www.safetyresearch.net/ https://www.users.ece http://www.cmu.edu/~koopman/pubs/koopman14_toyota_ua_slides.pdf http://www.safetyresearch.net/Library/ http://www.safetyresearch.net/Library/BarrSlides_ https://www.law.cornell.edu/wex/burden_of_ http://www.kellytechnologygroup.com/ https://www.law.cornell.edu/wex/preponderance

Table of Contents for the Digital Edition of IEEE Consumer Electronics Magazine - July 2017