Originally Posted by BHiC
To answer your question, if someone falls, then the point is continued. If the person had missed the shot, it would have been your point, and no hindrance/let could have been called. A hindrance cannot be called for falling down or for a racquet slipping out of someone's hand. Also, if a ball falls out of your pocket, or your hat falls off, your opponent must call the let. You cannot call a let because a ball falls out of your pocket. You are correct though that it is a let the first time, but then you lose a point the second time the ball/hat falls.
This had happened to me several times, I have both fallen down, gotten back up and won the point, and also lost points because I slipped and fell.
You actually have to make a call on yourself and lose the point if you:
dropped a ball, cap or any other subject on the court during point.
Just like in the case of double bounce.