This is the scene outside of the mansion on the final visit to Twilight Town, right?
In the Japanese scene the dialogue is:
ソラ:ãŠã„大丈夫ã‹ï¼ã©ã†ã—ãŸã‚“ã ?(Sora: Whoa, are you okay? What happened?)
ãƒã‚¤ãƒï¼šã‚«ã‚¤ãƒªã‚’探ã—ã«æ¥ãŸã‚“ã 。ãã—ãŸã‚‰ã€ã‚ã®ç™½ã„奴らã«è¥²ã‚ã‚Œã¦ãƒ¼ãƒ¼ (Hayner: We came here to find Kairi. Then we were attacked by that white guy). <-- this sounds super funny out of context ^^;
ドナルド:å±ãªã„ãªã‚ (Donald: That was dangerous...)
ソラ:ãƒã‚¤ãƒãŸã¡ãŒè²¬ä»»æ„Ÿã˜ã‚‹ã“ã¨ãªã„ã®ã«ãƒ¼ (Sora: You guys really shouldn't be feeling responsible for all this...)
ãƒã‚¤ãƒï¼šãã‚“ãªã‚“ã˜ã‚ƒãªã„ã£ã¦å‹é”ãŒã²ã©ã„ç›®ã«ã‚ã£ãŸã‚“ã ãžï¼Ÿ(Hayner: That's not it, our friend was in trouble okay?)
ソラ:ãã†ã よãªãƒ¼ãƒ¼ã¿ã‚“ãªã‚‚カイリã®å‹é”ãªã‚“ã よ㪠(Sora: Ah right...I get it now. You guys are also all her friends!)
My horrid translation aside, I think that perhaps this is more of a case where Sora hadn't realized that they considered her a friend.
When he bugs Hayner and the others about not feeling responsible he says it in a semi-chastising way, because it harkens back a tiny bit to the last time he visited. (After they explained how Kairi got kidnapped). At that time, they apologize to Sora for "letting" it happen, and he quickly corrects it saying "it isn't your fault, it's mine."
He was trying to let them know they shouldn't feel responsible for what happened. Then, he goes and finds out they were going out of their way to try and correct the situation anyway and he's like dude...I TOLD you not to feel responsible for this. Why did you put yourself in danger again?
Then Hayner quickly corrects him by explaining that they weren't putting themselves in danger because they still felt guilty, or "responsible" for her being taken, but they wanted to help her because she is their friend.
Sora immediately understands this and is like Oh! Well that makes much more sense then! You weren't acting hastily because you were feeling guilty, but because you genuinely wanted to help her as a friend. I get that.
I mean, that's how I read the scene anyway.