Krayzee is right, a switch to stop the timer without calling the event would be an absolute must. If people accidentally stopped the wrong timer or all of their timers then they'd do it the standard way and the event would be called, things could be 'corrected'. But there are plenty of situations (abuse of ON TIMEREND, simple debugging, etc.) where someone would want to stop an 'important' timer. It would be extremely arrogant for the scripter to just assume that he knows what's best for the user and for there to be no way for them to stop it short of editing the script.
In fact if anything the switch should be there to implicitly call the ON TIMEREND event. It might remove some functionality but it would then mean that the user has to specifically show that he didn't intend to stop 'important' timers. Or if not then the event should only be called when a wildcard is used or all timers are stopped with /timer(s) stop. I mean if I name a specific timer like /timerthistimer stop then I think it's pretty clear that my intention was to stop that timer, not to have it restart again behind my back.
