There appears to be a modification to this phone. - Steve Jobs' head is where the apple bite is. Maybe that caused it?
I do agree that the bite looks like a head, but it doesn't look the same as the one in the link above, especially when you take into account the missing "Steve Jobs" and "1955-2011".
I'd put it down to a freakish break line causing fragmentation around the bite. Backplate looks identical to mine (minus the damage).