DoubleNaught Spy -
You are correct, sir, one can hit what one can't see. Heck, I used to lob 8-inch shells at targets miles away so I can't dispute that. In the military realm where the rules of engagement are very loose as compared to an LEO mission.
I made the assumption, perhaps incorrectly, that this was a hostage rescue type of mission, and under those circumstances it would be unwise to shoot without identifying the target, hence the requirement for the light.
If you go into the room intent on killing anything, spraying and praying, that is not hostage "rescue" in any sense of the term.
I didn't do it, but I thought about it. Next time I might.