Hasn't crashed here so far.
Were any crash logs created? Automatic crash logs (for bug reports)
By the way, you should normally use DOpus.Listers.lastactive.activetab in an OnClick script. That could get a random window if you click somewhere else while the script is running. The clickData object provides you with both the active tab and a Command object which is pre-configured to use the active tab. Use those instead of creating a new Command and changing its source.
(I assume the rest of the script isn't the real one you're using, but something made to demonstrate the bug, since what it's doing doesn't really make sense.)