Re: video evidence from a freelance cameraman
this was in the UK ?
Trial judges are there to see the rules of evidence are followed, and one of those rules - a *fundamental* rule, is the concept of "disclosure", which means one side can't pull a rabbit out of a hat (no matter what TV shows you watch) and go "ta-da !". Woe betide any side that tries that in a UK court - the judge would go ballistic and very likely seek to admonish the offending side (prosecution or defence) with the costs of the collapsed trial.
In reality, if such video evidence only became available once the trial had started (since it's axiomatic that had it been available before the trial, there would have been no trial) then the defence would have approached the judge to introduce new evidence, at which point the prosecution (CPS) would have a chance to review it. I would suspect at that point, the CPS would then offer no more evidence, and the judge would direct the jury to acquit.
There have been courtroom surprises, but they are rare. The only one I remember was of a person arrested by the police in the 1990s (it may have been the poll tax riots). The police claimed they were arrested at such and such a time, which placed them at the scene of an assault. As the case was being heard, a series of photographs was shown to the jury, one of which showed the arresting PC putting the accused in the police van.
With his wristwatch clearly visible, and showing a time completely different to the claimed time.
Sharp-eyed defence lawyer spotted it, and started asking questions about police procedure for synchronising watches before operations, and was assured it had been done. They then queried the picture, and (if memory serves again) the judge immediately shut the trial down.