We already know that Zimmer was looking at acquiring K2M in the past. Strykers acqusition of K2M, in my opinion, was a move to buy future customers as K2M products were heavily used by it's surgeon owners. This, consequently, was why Zimmer passed on k2m as it was looking for real products without serious conflicts of interest. At least this is my guess from the 2011 post about Zimmer & K2M.
I believe those are there by insider arrangement. Dropping the shareprice bomb to allow those puts to be executed creates artificial liquidity that can break support.
Now.. as to how deep the collusion is that creates this "opportunity", I'm sure it's hidden in dark pools and such.