Eh, it happens. Nothing you can do about it unless you have an 82' Delorean, hand goes up and OUT I go. It's not cheating if you honestly don't know you have been hit, hell I paint check players on my side when I'm playing for that reason alone.
I would like to believe we all play fair and sportsmanship goes along way, letting that guy know you were hit but didn't know it after the game at least let's him know it was an honest mistake.
My gripe is getting shot out from the players that do nothing but scream for paintchecks on players the whole game. If you hit me and I felt it and it broke I'm out, save the paint checks for hopper or pod shots no cause you think you hit me.