So the spell was wrong from the start, that's why it happened. Not Dawn's fault then.
And for once Giles was nice... he still has difficulties when Spike acts different then the expects.
The good thing is that Anne's illness has a cure; only Ben isn't a good choice (but Buffy can't know that).

Author's Response: Yes TB was so deadly in Anne's time but can be cured (well, most cases) in this day and age. My mother tested positive and was in treatment for a year so I remember that well. k