I was on a jury, heard evidence in a hit-and-run. The witnesses: car was "blue", "dark", "green",...
The forensic evidence: Glass found at the scene exactly fit the broken places in the suspect's headlight.
The witnesses all were right, the car was "dark", it was night, no-one (except the drunk driver) was lying. But it was the forensics that removed any reasonable doubt.
A great example of the relative worth of eyewitness testimony and physical evidence. Thanks!