Not a professional or anything, but I think「たぶん気つかったんだらうなあ」might be something like "Probably trying not to worry anybody" or something like that, going back to how he was trying not to show it hurting. Basically showing a brave face to avoid being seen as ruining the mood in any way. Not particularly confident in my Japanese grammar but to me it felt like a shortening of「気をつかう」( versus 「気づく」 or「 気がつく」 for notice.