An 'Oh great...' wou;ld have ruinbed the line!
Well, if you guys don;t think it is sarcasm then fair enough.. I do, and I maintain that's exactly how I would have delivered it. And I think that 'Why do I sense...' line makes it out to be VERY sarcastic! That's certainly how I write.
Qui-Gon was just unimpressed by the sarcasm, I thought, because Quoi-Gon was so earnest about Anakin. he wasn't actually reprimanding Obi-Wan for being dismissive, just he thought it wasn't an appropiate thing to make fun of.