I once had a pretty random glitch on Stuntman. (The first one on PS2)
On the final level there's a stunt where you have to hit a ramp and jump over a swimming pool, through a gap between 2 diving boards. (a high board and lower board).
At one point, I hit the jump a little skew-y and clipped one of the boards. My car, at this point, would fall into the pool and the level would end in failure. On this occasion though, my car hit the water, then inexplicably flew into the air and away over the rooftops. It was as if the water acted like a super bouncy catapault. The camera didn't follow the car, it had already cut to the 'failed' angle, so all i could do was watch my car disappear over the rooftops.
Completely mad. Never happened again.