I dont doubt that a stray round couldnt come back and hit the plane, though IMHO I find it highly unlikely. Watching the rounds impact in the video, they seem to spread out in almost a fan shape away from the target. But if possible, add it to the game as well to increase the danger of attacking very low to the deck. (on a side note, has there ever been a example of it happening or recorded)
Could be a compressor stall as well, if the engine doesnt respond right to different varables (temp, humidty, pressure) among other things, it very well could have been a compressor stall. But with smoke filling up the cockpit, they might of even had a engine tear itself apart, as would be the result of the loud bang they heard.