I think the telepathy thing, which confused me at first, is possible, think about it.
I would suspect Willow could do it. Being a witch and all, anyway.
If Buffy was thinking, loudly, as Grounded stated, Willow,could have picked that up, then Willow telepathically talks to Xander, Willow can here their two thoughts, becuase Willow doesnt really talk, Buffy does all the talking, then Willow could have told Xander what Buffy said, we just didnt see that.
And yeah, BuffyUKer i do downloads eppis sometimes!