Oh, and I thought of a real point as well. I agree that Xander doesn't get any moral credit here, any more than Spike got credit for not feeding off bleeding disaster victims.

That said, I'm not sure the show was wrong to have Buffy praise him. From a pedagogical view, her praise reinforced the fact that he did the correct thing. Now, I'd like to think that the correct path was so obvious that it didn't need reinforcement (like Spike's case), but sad to say that's not the real world. For this reason I wouldn't criticize the show for hanging a lantern on the point.