Trejo downplayed his contributions, saying "The only thing that saved that little kid was his car seat."
"It's only now that I'm realising that we probably saved his life," one of the officers said.
"Sorry, just some cars have had a bit of a crash behind us," Alison Freeman said.
Days before doctors were scheduled to transfer one of the fertilised eggs into Liu, the couple died in a car crash.
Another U.S. state just passed a law allowing "wildlife salvage."
Los Angeles, Chicago, and New York City account for 42 percent of pedestrian fatalities.
Improving economy, lower gas prices among reasons suspected for increase in traffic deaths.