Absolutely right. Until relatively recently I was against people filming everything all the time. Seems ridiculous, and annoying. Unnecessary.
However now, and especially after the Henry Nowak murder (where we'd all have been told and believed it was his racist attack on the poor brown people, had Henry himself not filmed part of the interaction; and of course the police recording of the killer and his accomplice brother talking in a foreign language (Urdu?) in the back of the police car), I hope people film everything, and I will too if need be. We can't trust the truth to be told otherwise, as we've seen