Pretty rare.....would be a rattling experience!
Best wishes that he heals without complications.
Shark attacks Brazilian scuba diver during Unesco marine preserve dive | World news | The Guardian
Some sharks have been fed by humans and some point in their history and have a memory like a dog.They are curious when divers enter the water and have developed a pattern of investigation and may include a bite. I have seen aggresive reef sharks from cayman brac to fijji and they are probing for food around divers even though the dive master says they do not feed them anymore. Feeding can be an issue which leads to some sharks become way to curious.