When Experts Apply Bad Data to the Wrong Standards

Welcome to October.  As in years past, I have decided to make reading this blog the second coolest thing you could be doing (watching Shark Week is still the coolest, but watching Sharknado is a distant third) by dedicating this month’s posts to expert witnesses.



Reliable, admissible, persuasive expert opinions must do many things.  Among others, the opinion use reliable data and the correct standards.  It is not fun as a lawyer to later learn that your expert’s data is unreliable and applied the wrong standard, unless you are the opposing lawyer deposing that expert, like me earlier this year.[1]

The case was a generic trip and fall in a local store of a national retail chain.  The customer asserted she tripped over the sales sign.  She filed suit and sought to prove the duty and breach elements of negligence via negligence per se.  She hired an expert witness to conduct a site inspection and then relied upon the expert’s findings to argue the retailer was negligent per se.  As usual, I have omitted the names of those involved because this blog’s goal is professional advancement, not attacking others.

I eventually deposed the expert.  His first opinion was the aisle where the customer tripped was too narrow.   He argued various standards required the aisle where the customer fell to be a minimum of 36” wide.  He concluded it had not been 36” wide when the customer visited.  The problem for the expert was the fall occurred in September, 2014 and the data upon which he relied was not gathered until February, 2016.  The area where the fall occurred consisted primarily of moveable goods.

After quizzing the expert about a slew of missing information, he conceded he could not correlate what he found in February, 2016 to what the customer experienced in September, 2014.

21:16           Q.     Would it be fair to state that you can say,
17   to a professional degree of certainty, that your
18   measurements on February 10th of this year indicate a
19   potential code violation, but we cannot correlate that to
20   what [customer] experienced on September 1st, 2014?
21           A.     I can correlate it to what she had testified
22   to.  But as far as any specifics with respect to
23   documentation, photographs, measurements at that time, I,
24   unfortunately, am not afforded that.
25           Q.     So it’s possible that she encountered the
22:1   same conditions that you measured and observed, but it’s
2   also possible that she encountered something different?
3           A.     It’s possible.
4           Q.     Is there any way for you to say, with a
5   professional degree of certainty, whether the aisleway in
6   which [customer] fell and the location where she fell met
7   that 36-inch requirement?
8           A.     That they had adhered to that 36-inch
9   requirement?
10           Q.     Yeah.
11           A.     I can’t state that, no.
12           Q.     Because we don’t know the measurement from
13   that date?
14           A.     Right.

I had no more questions about that opinion after this answer.



The expert’s second opinion was that the elevation change of the floor caused by the sales sign breached various standards.  The problem was none of them applied to the customer.

The first standard was ASTM F1637.  Nevada “has limited its recognition of negligence per se claims to violations of building code, traffic statutes, and municipal codes.”[2]  In other words, negligence per se only occurs if the provision at issue has been adopted by a legislative body.  The expert conceded in deposition that ASTM F1637 has not been adopted in Clark County.  Consequently, ASTM F1637 it could not be used to prove a negligence per se theory.

Next, the expert relied upon the Americans with Disabilities Act Accessibility Guidelines Manual.  However, “the ADA does not fall under the class of statutes that the Nevada Supreme Court would allow as a predicate for negligence per se.”[3]  Consequently this too could not be used to prove a negligence per se theory.

The expert’s final standard was ANSI A117.1, but it did not apply either. The Seventh Circuit addressed this question in Maurer v. Speedway where a customer at a convenience store fell off a curb.[4]  She relied upon A117.1 to assert negligence per se because the walkway where she fell was 24”, not 36”.  Like Nevada, the standard had been legislatively adopted.[5]  However, it did not apply to this plaintiff.  “The stated intent of the ANSI standards is to ‘allow a person with a physical disability to independently get to, enter, and use a site, facility, building, or element.’”[6]

Specifically, the technical criteria adopted in Chapters 3 through 9 (i.e., including Chapter 4, the relevant Chapter here) of ANSI A117.1-2003 was designed to make buildings accessible to people with physical disabilities, such as “the inability to walk, difficulty walking, reliance on walking aids, blindness and visual impairment, deafness and hearing impairment, incoordination, reaching and manipulation disabilities, lack of stamina, difficulty interpreting and reacting to sensory information, and extremes of physical size.”[7]

Although “nothing in the Ordinance or its sparse legislative history expressly limits the applicability of the incorporated ANSI standard to physically disabled persons, we think it would be remarkable if we held that South Bend officials sought to transform what is plainly meant to protect disabled persons into one protecting the general public.”[8]  The court refused to interpret the standard more broadly.  It then affirmed the district court’s decision to exclude A117.1.  “Because Maurer was neither disabled nor confined to a wheelchair, she does not fall within the class of persons that the Ordinance and incorporated ANSI standard was intended to protect.”[9]  This ruling was consistent with Rising Moore v. Red Roof Inns, Inc. where an expert’s opinion relying upon A117.1 was excluded, in part, because the plaintiff was not disabled. [10]

Applied to my case, the expert repeatedly conceded during his deposition that he reviewed no evidence indicating the customer was disabled before she fell at the store.  In fact he gave me a strange look each time I asked the question.  Regardless, if the customer was not disabled, then A117.1 was inapplicable and could not be used to establish negligence per se.

What happened next?  Motions were filed about these topics, but were never decided because the case resolved.


[1] This was the third fun expert deposition I had in 2016. The first two were discussed on May 23, 2016 and July 25,2016.
[2] Westbrook v. DTG Operations, Inc., No. 2:05-cv-789, 2007 U.S. Dist. LEXIS 14653 (D. Nev. Feb. 28, 2007).
[3] Id.
[4] 774 F.3d 1132, 1134 (7th Cir. 2014).
[5] Id. at 1136.
[6] Id.  (quoting American National Standard Institute, Accessible and Usable Buildings and Facilities 2003 1 (2004)).
[7] Id.
[8] Id.
[9] Id.
[10] 368 F. Supp. 2d 867, 870-71 (S.D. Ind. 2005).