Friendship ruined by 50 pence piece?

I play snooker every week with my best friend Stuart. Every week I buy 3 of the delicious ham cobs on sale. Unfortunately I don't like er, and so each week I scape the er off with a 50 pence piece. I don't know how I did it, but I must have left the coin inside my ham cob. On my shot, Stu asked could he have a quick bite of my ham cob, and before I could reply, there was a sickening crunch. His face contorted with pain and he let out what I can only describe as an almighty man scream. It didn't take long for me to deduce what had happened. To cut a long story short, he broke 2 back teeth. He now needs emergency dental work, and believes I should pay for it. My argument is that, I didn't ask him to have any of my ham cob. It wasn't as if it was a prank or anything. What do you think? Should we fall out over this ?