All good experience Tom.
As a result of newby collisions my mates have broken 3 pins and lost one brace while sailing my spare AI. None have capsized despite two of them occuring in winds of 15-20knots.
Your post has reminded me to post a clip I have of sailing back with a broken brace pin and holding the aka out to prevent capsize. I'd recommend everyone have a try of this so that if it happens the results won't be so unexpected. Disconnect the brace from the ball and try holding out both lee and windward ama (not at the same time). It's not that hard, though it can get tiring if the winds are strong and land is a long way off! Probably good to practice replacing the pin at sea as well so that you don't have to exert that arm!
Because of K-Bobs leashes I keep the spare pins separately. If the spare pins are still on the brace make sure you can undo them easily, or you have access to a tool to assist, as they can be tight.