He doesn't avoid it, but he does tense slightly. Guess who's still unused to random physical affection, hint it's this guy. Hell if he knows what he did to deserve a hair ruffle, either.

"More importantly, are you going to be alright? If you can't talk..." Well, for one thing, he probably figured it out because he tried to say something and was immediately punished through the bracelet. And for another...

Being unable to speak would make communicating with Snake incredibly difficult.