Ehhh... ok, perhaps not forgery, but it's still bad for the overall situation isn't it?
I suppose there are some instances where maybe it's not so bad to let someone else continue with an incorrect assumption they've made about you, but I'm really pissed that she would let this go on. I mean, if you're going to come forward with this, you obviously want people to know about what Moore did. Why sabotage the entire effort by letting people run with something like this? Why not just say "no, no, he really did sign it ...but the rest are my um..'notes'"?
The problem is that now the smug defenders have something to point to. Even if it doesn't honestly resolve the matter, they can point to it. And it is a rather unfortunate human predilection to latch onto something like that and dismissing everything of like kind, even if it's not logical.
Granted, there are a lot of people who don't care either way since they were prepared to vote for him even if it was 100% true. What of people on the fence? Perhaps, the less-than-entirely-bright people on the fence?