"Makin' me worry like that," said Heiji, grumble grumble. "Don't even know why he did it; it's not like him to go haring off like that. If he messes with that bandage of his, I'm really gonna lay him out."

...So basically, a large part of Heiji's complaining was simply him worrying about Snake. Sorry bro, but now you knew why he acted like this.

"...Really? I understood him just fine, though." Tsunspeak, it was like telepathy. "I mean, there are some things you just can't come out and say. Know what I'm sayin'?"