Surely it's about the end user and whether it's intuitive to use or not? I don't think the end user would say calling a button 'Back' is obviously the button for stopping recordings.
You've saved one button but it's not the best remote to use, exiting from the Recordings menu for example takes a minimum of two button presses because there's no Exit button.
Back to your original question. I'd expect a Stop button to stop a recording and to stop time lapse, Back stops a recording but doesn't stop time lapse, in fact nothing stops it apart from fast forwarding as far as I know, again not exactly user friendly or intuitive.
