*Membership spots not really limited!
I agree that it doesn't make any sense but after reading Nightwing #7 I can safely say that:[Reveal] Spoiler: Click to ExpandThe tooth is only shown after Bruce backhanded Dick. I can't debate you on the rest of your argument but if I hadn't already read Batman #7, I wouldn't have even known there was another tooth. This may have been an oversight but it certainly looks like they want you to believe that the tooth is Dick's.
except that they spend an entire page in Batman #7 explaining the tooth thing while standing over the Talon's body. may be that we have to lay the blame on Capullo's storytelling if they really don't show the tooth prior to the slap (i don't remember, would have to re-read)