Literally irrelevant.
Sanji was already hurt beforehand when his leg was cracked against Vergo. I'd take my leg getting cracked out being incapacitated any day. That comparison with Luffy is stupid because Luffy whipping out G4 would be the equivalent of Vergo using his FBH. A fresh Smoker got punked while a Sanji came out with a minor injury.
Law on his mind? He mentions Law after the fight. What Vergo wasn't even concerned about Law when the fight started and only mentioned him afterwards. Not being top priority =/= Not being taken seriously. I guess Pica wasn't taking Zoro seriously because he wanted to fight Luffy instead now?
It still holdS no weight because when Sanji was being 'out kicked he wasn't even using DJ.
Oda gave no hints during the fight that his leg broke because of his injury, therefore the injury played no role in his leg breaking.
Stop using that as a bail out excuse. Oda is the type of author to always let you know if an injury played a part or not. What about the kick simply being strong enough to crack his leg? How about that, have you ever thought that one through?
He was injured (hardly) = true.
His leg cracked because of the "injury" = not true.