I tried flying with doorgunners once, then got into a dogfight with a Mi-8. Both gunners would aim at the enemy but didn't shoot. I was holding the heli straight, 90 degrees off him, but the gunner still just looked. This happened in multiplayer, and i never tested it after that, but it surely frustrated me. My gunners also seem to cycle the firing modes on their own, without me pressing anything, which results into copilot flicking the switch from rockets to miniguns, i then fly at the target ready to fire my hydras, can't do it and die.