Mine have never gotten out when I didn't know about it, but having two gates that cannot been seen from the door where I let them out, it is a worry.

The most unusual way my dogs have gotten out was when they and I were in the garage, on our way back into the house, and I put my hand out to steady myself against the wall so I could remove the boots I had on....and I accidently leaned on the button for the garage door opener. The garage door started up and they zipped out before it reached 3 feet.