And, WHY is what happened still a mystery? Aren’t FBI agents trained to be expert witnesses? Weren’t they there? Haven’t they had enough time to all record their testimony - multiple times.
So, what is REALLY going on then?!
They need time to carefully edit any video from cameras they had with them.
If they claim they didn't have recording equipment with them (which is most likely a lie), the question would be "why the frack not?"