There is a sensor in there that will trigger the door to retract, i have only had two CD/DVD drives fail, both were 6+ years old and never had their button pushed. Disk drives are quite robust and most of them don't have their button pushed to retract the drive because it isn't easy to reach on most systems(i would have to sit on the floor to get to mine). You aren't going to kill the DVD drive, and even if you do they are super cheap these days.