Not gonna lie this "not firing any bullets" tactic completely flew under my radar, but I must say I kinda like it :) It's almost like for a people that say "f*ck this map, I'm outta here". Also your time beating this in 11 seconds even with this pacifist route is really impressive.
I set the destinations intentionally for the player to be in this "sandwich" situation where once the pressure is too high you need to fire BFG in order to reposition yourself. If the destinations were changed so the player could just run out of the corridor it would be much less impactful fight. I'm sure you get the point :)