Maybe. I don’t know what their threshold is for validity of a report before they take action.
I do think that if the officer had tried to intervene and gotten shot, the guy would have immediately been shot by one of the snipers, maybe fast enough that he wouldn’t have gotten a shot off at Trump. All I can do is speculate; I don’t know what their policy is. But in his place, I probably would have done the same kind of thing, like putting my hands up and taking a step back until I get reinforcements or snipers take him out. But I guess there wasn’t time for that.
But yeah, after confirming a gunman they definitely should have hustled him off the stage.