Nobody is doubting it was an act of violence. The oddity is that they're calling it an act of murder as opposed to an act of war. Murder sounds like a bunch of criminals, which is a really one sided take. The british soldiers were there to destroy colonial military supplies. It may be technically correct, but you don't hear about how the GIs murdered a bunch of Nazis on the beaches of Normandy or whatever other war suits your fancy. Save for the particularly one sided conflicts.

I got history from american public education, and while half of it was garbage, and half of it was dull internal politics of isolationism, there was no ambiguity that the revolutionary war was a bloody conflict.