No, it wasn't a double post. I hadn't touched the submit button previously. I know that because it was hidden under the Nexus keyboard. So it was only hit once.
ETA: LOL, it's messing with me.

This time it did do a double post, despite me only hitting submit once. Then, when I deleted the extra post, it said it was returning me to the forum and I ended up in Fanfic!!

oh, well, guess in half an hour it'll be working fine again.