By concept alone, once I charge that shot up, there should be nothing that interrupts the shots from leaving the chamber of the fusion rifle. I have ZERO issue of the mechanic of me being able to interrupt the actual charging of the shot by punching someone or whatever the hell it is (yes I'm mad) but after I spend HOWEVER LONG THE RIFLE REQUIRES ME TO CHARGE A SINGLE SHOT AT THAT MOMENT (worded for Merciless to not be left behind) all bolts should leave the chamber and fire out of the barrel. I'd love to know any other reason why it should be different. Edit: and I said nothing about how accurate it would be...if you hit me with something or make me flinch by punching me I have to be good enough to control and aim that shot still. That's on me as it usually is.
This has been an on-going issue since D1. Bungie has remained quiet about why they keep this.