Dont believe everything you read ALF. Im sure airmen reported this, but it cant be true. The .50 cal in particular, but ammunition as a whole regardless, hug the ground when they ricochet. It is possible that airmen saw tank crews abandon the vehicle when they attacked and counted it as destroyed, or they somehow lit the things off with incendiary rounds hitting fuel vapors (tanks leaked and thats a fact), but no way could a .50 bounce off a road and still carry enough energy to penetrate armor plate.
I have never had that misfortune Ouch. I have shot down as many as ten planes from the pintle in one sortie, taken hits from .50s and 20mms, but if they could kill you then why havent we heard of a wounded driver or commander?