Except that eyewitness testimony is never uncritically accepted in any justice system. Ask a group of people who observed an event and invariably there will be a substantial portion who remembered basic facts about the event wrong. This phenomenon is well understood. Furthermore, there is a difference in asking about the phenomena a person observed and a causal event a person was a part of. An eyewitness can be confused about any number of specific details but it is much harder to be confused about an event that had a direct impact on them. In the latter case, we are not blindly trusting their recollection but rejecting alternative explanations as lacking causal power.
Accepting hard evidence doesn't involve trust at all. You don't trust a medical lab not to fabricate evidence; you rationally judge the probability that they went to the effort for no gain whatsoever and risked their reputation and career on something that would be subjected to intense scrutiny in a courtroom on the hope no one would notice something was amiss. Of course, the defense has rights to directly question and propose an alternative explanation. A court doesn't accept evidence blindly.
>> Want to claim crazy or spontaneous mass hallucination? Prove it. Show the mechanism in the brain. Reproduce in a lab. Put a name to the disease. The burden of proof is on you to describe why our justice systems are built on a complete farce.
Nonsense. It is up to the person claiming a radically new phenomena to show evidence and proactively demonstrate that there is no possible alternative explanation. This isn't unfair, if you can't examine the explanatory power of other theories your own theory should probably not be accepted. Do you declare at the end of a magic show that you have just witnessed a supernatural event unless a person can explain to your satisfaction exactly how the tricks were done? Furthermore, you are going further and asking for counter evidence that does not rationally match the standard of evidence you have actually presented. As I just pointed out above, the justice system does not uncritically accept eyewitness testimony.