I mean of course if not 10,000 people could stand in a room, watch someone murder another, and then all 10,000 come and testify exactly who it was and what the jury would not be allowed to convict?
How about one person and a rape accusation from 20 years ago?
If 10000 people witnessed a crime for which there was no physical evidence present, yeah I'd say something is very suspicious and would not convict.