Even if they were a bit twitchy, it was still bad drills what about good old all round defences if it was me I would already be digging a scrape and if you are under fire and decide to get out of your Humvee then why standabout next to it, it will attract fire like a magnet.
I would worry if someone I was with decided to wave one of those around, in fact they would politely be told to get either under cover in back in the vehicle until they find a proper rifle to bring to the fight!
Probably more danger of shooting his own than the enemy!
Can't speak for other units, but we found it was the best way of finding the enemy: Get them to shoot at you. It's bloody hard to find an IED trigger man these days just by looking around. Our platoon used to do it one of two ways: Repeatedly show up at the same place at the same time, and look casual, or undertake "Operation Suicide Bait" which involved two of our under-armoured HMMWVs driving down the road headlights on with 'shoot me signs' with the tanks about a mile behind in blackout drive.
Man alive you Americans are tough on crossing drills
After they fired at yet another vehicle which drove to our checkpoint at excessive speed, the 1st Sgt of the unit we were attached to remarked "If we do nothing else in this country, at least we'll eliminate speeding"