It was more of a criticism of how, to you specifically, you view things void of any context, nuance or human emotion and it can only ever be construed as x. Which is nonsense. You do it with most other arguments. You look at the end result, take away any context or human nuance / common sense and accept the worst case scenario as truth. So you're in no real position to talk about communicating / discourse etc either.
To this topic - it's still not a death threat. I'm not too sure about BLM / Sanders so I won't comment. But if anyone here was to give a speech and someone in the crowd did a hand gun gesture, I really doubt they'd take it as a legitimate death threat. Only you or an overly PC sensitive moron like the guy in the link would.