So this rule assumes that the motion detector goes back to 0 after a certain amount of time. That time should be less than FE02_TimeOut or else the rule will not trigger often enough to reschedule the timer.
I don’t think you need the checks in the Timer body on the motion detector. The Rule itself handles rescheduling the timer based on motion so you should never hit a situation where the motion detector is 1 when the Timer actually expires.
Just make the body turn off the light and set the Timer to null.
OK, so there might be an exceptionally rare case where you end up in a TOCTU situation but I wouldn’t go out of my way to address it unless you actually experience a problem. And if you do experience a problem, rather than checking for the state of the motion sensor in the timer, put the rule and the timer body inside a reentrant lock so the two can never run at the same time.
And just in case you didn’t see this example: