How annoying, good thing your guy was nice to you about it.
I was on my TB once going down a hill ( large kinda steep ) and he started bucking , and just to add a bit of fun to the situation my cross over bittless bridle broke and slid up his face

. He stopped about half way and I quickly jumped off, the bridle wasnt to bad just some stiching had come loose and broken under pressure. I was just lucky I was still in the paddock when it happened.........Also found out a little later he bucked because he got a small peice of wire wedged under his shoe..proberly quite uncomfortable for him.