Did anybody notice that Karo is claiming he was prescribed the pain-killers while training to fight Hughes? Not that it matters, but it's still interesting to note.
Honestly, I have never been a Karo fan, but I can understand why he hid it if he actually has a problem with pain-killers, as it would seem he does if he still using them and hiding it from people over 4 years after the fact. Regardless, banned substances are banned substances and he KNEW that. So, it's his fault no matter what.