Manny Lopez v. United States, 790 F.3d 867

On Aug. 13, 2009, Lopez (passenger) and driver Shea Pyron were northbound on Tucker Blvd.; Pyron merged from a "run out" lane into the through lane and stopped at a red light just before the intersection.
A USPS tractor-trailer driven by Robert Cleveland struck the rear of Pyron’s car; Cleveland later died and could not testify at trial.
Lopez sued the United States under the Federal Tort Claims Act alleging Cleveland’s negligence caused the collision; the case was tried to the bench.
The district court found Lopez and Pyron’s accounts inconsistent and credited Officer Janet McKern’s on-scene investigation, concluding Pyron had abruptly merged and deprived Cleveland of time/distance to stop.
The court entered judgment for the United States; it denied Lopez’s new-trial motion. Lopez appealed, arguing (1) the Missouri rear-end presumption entitled him to judgment and (2) the court erred by admitting Officer McKern’s causation/opinion evidence.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Applicability of Missouri "rear-end collision" presumption	Lopez: collision creates prima facie negligence against the overtaking driver (postal driver)	United States: Pyron turned/merged in front of Cleveland, creating immediate hazard and excuse; presumption overcome	Court: Presumption defeated—evidence showed sudden merge that denied time/distance to stop; judgment for U.S. affirmed
Sufficiency of evidence / credibility after court trial (new-trial standard)	Lopez: trial court misweighed evidence; new-trial warranted	U.S.: district court’s factual findings and credibility determinations supported by substantial evidence	Court: Abuse-of-discretion standard met for district court; findings not clearly erroneous
Admission of Officer McKern’s opinion and report	Lopez: officer was not a qualified reconstructionist; her causation opinion and comment that such merges are common were inadmissible	U.S.: evidence admissible and, even if not, sufficient competent evidence existed without it	Court: Even assuming error, sufficient competent evidence independent of McKern supported judgment; no reversible error
Claim that prior summary judgment for Pyron binds FTCA outcome (law of the case)	Lopez: earlier summary judgment for Pyron on negligence should bind this issue	U.S.: argument raised without authority; waived	Court: Argument waived and not considered

Chapa v. United States, 497 F.3d 883 (8th Cir. 2007) (standard for abuse of discretion on new-trial denial)
Richardson v. Sugg, 448 F.3d 1046 (8th Cir. 2006) (review of factual findings and substantial-evidence standard)
Culpepper v. Vilsack, 664 F.3d 252 (8th Cir. 2011) (credibility determinations rarely clear error)
Dolan v. U.S. Postal Serv., 546 U.S. 481 (2006) (FTCA applies to Postal Service activities)
Green Acres Enterprises, Inc. v. United States, 418 F.3d 852 (8th Cir. 2005) (FTCA liability measured by state substantive law)
Kaufmann by Kaufmann v. Nagle, 807 S.W.2d 91 (Mo. 1991) (rear-end presumption inapplicable where vehicle turns in front creating immediate hazard; time/distance factor)
Clark v. Belfonte Distrib., Inc., 163 S.W.3d 581 (Mo. Ct. App. 2005) (describing Missouri rear-end collision doctrine and rebuttal by defense evidence)
Greater Kan. City Laborers Pension Fund v. Superior Gen. Contractors, Inc., 104 F.3d 1050 (8th Cir. 1997) (trial-to-court may include inadmissible evidence courts are presumed to ignore when sufficient competent evidence exists)
Arkwright Mut. Ins. Co. v. Gwinner Oil, Inc., 125 F.3d 1176 (8th Cir. 1997) (appellate review standard for admission of expert testimony)