That's not actually a Bitcoin double-spend, though.
This. Quit talking about double spending, this is confusing. Notice that MtGox communication don't talk about double spend at all, either.
It's just a
voluntary MtGox double send.
Yes, that is a more apt naming for it.
I just examined an outgoing transaction from Mt. Gox that I made earlier and how it got noted in the blockchain. Their regular scriptIn seems to be with an uncompressed pubkey. Anyone seen different scriptIns from Mt. Gox?