Not in a televised campaign debate.
It's one thing to mis-speak when you're on the road and surrounded by a gaggle of reporters asking off the cuff questions. I don't know any candidate who hasn't committed a gaffe under those circumstances.
But in a live debate, which you've no doubt spent considerable time preparing for? Disastrous. Even more-so, considering that he's goofed like this several times already in the debates.
I saw it. I thought is was funny and well handled. I thought Perry looked fine when it happened.