Here's a situation I ran in to last week and it got me thinking.  Third game, 10th frame.  I've already finished out the last frame for our team.  The final bowler of the other team goes 9/ and needs 6 pins to take the game.  On his delivery he sticks on the approach and tosses a 4 count but he falls forward and plants both hands on the lane, clearly a foul.  He went far enough past the foul line that the lights didn't pick it up.  

Now, noone called this foul.  It had no effect at all on the outcome of the score sheets.  But I am wondering if I should have called it and if so, would he have gotten the provisional ball roll?  I see in the rule book that he would if there was a dispute but there's no way anyone could honestly dispute the foul.  

I am thinking that the 4 pins should have come off the score and it be left at that.  But as I said before, it really had no effect on the games.  I have no intention of following it up and saying anything about it, I am just curious how it would be handled in a situation where it would have mattered.