Of course, I'm just sayin... I have seen people knock their opponent out as they were falling back. Even more common when they are still on their heels and have another few steps before they actually go down. And of course we have all seen the over ambitious guy fall right into a submission because they were too offensive.
Timing is very important, even when you have your opponent reeling backwards. I know you know this.
edit: you do see some people give up top position for submission attempts from the bottom all the time.