The "laughing" scene

[ReloadPsi]

Okay, the impression I've gotten lately is that people think the voice acting is bad in this scene (as if they haven't got the rest of the game to complain about, geez)

Am I the only person that realises Tidus is not supposed to be actually, genuinely laughing at that particular moment? Isn't he supposed to be severely downtrodden and basically taking the Michael when Yuna tells him to "try laughing out loud"? I know they both burst out laughing afterwards, but the impression I get is that's not what people are complaining about, it's the fake laugh before it.