Sometimes with a cellphone video you'll see cops behave bizarrely, abruptly shouting things like "stop resisting!" or "gun!" when it's obvious the suspect is not resisting and is either unarmed or not reaching for a weapon. The point of it is to establish, on less revealing recording devices such as bodycams and dashcams, that the officer has a reasonable fear for their lives. That fear is held to justify anything bad that might then happen to the suspect, even if it turns out to be mistaken. And so the weird yelling about guns and impossible movements becomes a ritual to that end.
Which is to say, if a cop starts shouting "gun!" during an interaction with you, that cop intends to kill you.
And if the cop is poking his gun at you sideways like a cartoon gangster? You better get lucky fast.