I agree that you're super unlucky, and it sucks, but it's surely not impossible.
Imagine perhaps that the opponent is corralling him, looking to give the intentional foul, and instead of sitting there and taking the foul, your player tries to run the clock some more by dribbling away and avoiding the fouler. As your player dodges to the left, the fouler reacts clumsily and tries to follow him, sticking out his leg as he moves, and catches the leg of your player - who is tripped and tumbles to the floor.
I think if you use your imagination there's usually some kind of realistic explanation for most of the wacky things the BB game engine throws up, even if they are a little far-fetched or unlikely.