The truth and facts will come out in court - not in your living room.
Hypothetically, let's say I am suspected of a crime that was caught on tape. I am asked for a statement as part of the investigation and that statement will probably be used as evidence.
Would I not also be allowed to review the video before making my statement to refresh my memory, just as our brave boys in blue?
the reports are used in court. if they are corrupted, it makes getting at the truth in court more difficult.