You are RIGHT to be VERY concerned!

Flipping the boat always has some hazards. You may get brused up a little, but you'll heal. Its rare to do any real damage, but it can happen. The truely cautious will always wear their life preserver. (but I don't so I am taking risks, which I may regret some day.)

But falling off the boat has different risks. When the boat starts to tip, stay to the TOP side of the trampoline and slip into the water, then quickly get out from there in case the boat decides to turtle on top of you (doesn't usually happen). Then stay in contact with the boat at ALL TIMES, as you go throught the routine of righting the boat.
If you can't right the boat solo, at least you can stand on the hull until you are assisted or rescued.

But if you fall or drop off to the bottom side, there is a chance you may get seperated from the boat. QUICKLY get to the boat. If the wind was strong enough to flip your boat, there is a good chance the wind can push your boat faster than you can swim. If you get seperated from the boat, as hard as you swim, it just keeps getting further away. If you sail a small or medium sized lake, this is just real annoying. But if it is a large lake or the ocean, well for your sake, I hope the wind is blowing into the nearby shore.

These possibilities are well worth considering, before they actually happen.