Whey they would NOT show was this guy reaching for a gun. They would have shot him before any scuffle had that been the case.
This is probably true, but this is not an empty set.
If they had a good reason to grab him it might show in these videos , but I expect that the bodycams are showing misbehavior on the part of the police.
If what the bodycam shows is that the policeman turned the thing off just before beginning this confrontation this would be a malicious dereliction , it would show an intent to hide the truth, before there was anything to show.
If the knowledge that a person has a gun is by itself probable cause for arrest or reasonable excuse for policemen to knock you down, then the second amendment means nothing.
What happened in the moments immediately before this altercation is important to know.
If the police instigated the violence , they should be held responsible for the violence.
If they had the means to record that moment , and willfully refused to record that moment , then I think it reasonable to assume that they intended some bad behavior.