From my local paper - It's only a mistake if you don't learn from it.
Hormones are always to 'blame', sometimes good, sometimes bad. We're just a chemical concoction, dontcha ya know?
There are times when I do open my mouth despite my intention not to. I step back from the conversation (not so gracefully, usually) then 'do it over' at whatever point I feel calm enough to do that - 20 minutes later, the next day - "I didn't express myself very clearly last time we talked about x. What I meant to say/what I should have said was y."
I do this for me and not just with my H, because I'm uncomfortable about the way something went down. Regardless of the response, it makes me feel better.