Why would you deviate prior to landing at your final destination in the first place? I never do until I know I made my deviation flight, for this exact reason. You are deviating from the trip not a specific leg was always my understanding. This is why the deviation requirement on a back and deadhead is not near as restrictive as the time required on a front end deadhead. I am not saying I agree with the outcome but don’t understand why an individual would deviate so early on the backend of a trip.