Well, maybe I should have said "very, very, very unlikely anything bad will happen if it is pressed accidentally." A failure of the interlock that prevents engagement while in motion is very, very, very unlikely, but pressing the button while moving is still a bad practice, sorta like "why go looking for trouble."

I wouldn't worry about it. I had/have the same habit, but after a couple of months with the X5 I'm mostly over doing it.