[So far, Sabo had been choosing his words carefully. He doesn't know how far his brothers trust this Marine, only that Ace can have a fairly decent conversation with him, and that Luffy basically treats him like a friend despite being enemies. (But then again, that's Luffy; he's always an exception to any rules.) And Sabo's not exactly aware that he's already been revealed as the third brother, so he's just being cautious here.

But... you know what? He can't help bursting out laughing at that pun. And the utter ridiculousness that is the D luck, after.]

Oh man, that's insane! A-a freak lightning?! A-and a rainstorm? Ahahahaha! Damn, that guy's luck is really, really incredible! [Laughing some more until he needs to catch his breath. And his bias might be showing now.] And? They managed to get away, right?! Did the Marines chase 'em to the sea too?