Woa! That's scary. Until some programmer type gives a full answer here is a possible work around. For one you could turn off auto-save but auto-save is good. I sometimes put in an extra address line "not yet" which is an invalid address. Forces me to think before sending and avoids accidentally sending. You get a "can't send because of invalid address" error. When you're ready you remove that address line.

I will be very interested to hear what the full answer to this nasty quirk is.