Yup, it gets a bit more tricky sometimes when trains that stop at Avoncliff and Freshford have 4 coaches and there is no walk through between the two units - There was a chap who wanted to get off at Freshford but he was in the rear two coaches on a service last week and he couldn't get off, and then something snapped when we got to Avoncliff and he forced the doors open and jumped down onto the track... He should've just waited three minutes for Bradford On Avon, as that station gets all the trains Avoncliff does!
Usually with the awkward seating lay out if the train is a 150/1 (the 2+3 seats) the guard will open the local door using the furthest doors from the driver's cab in the front carriage. It all gets a bit confusing sometimes, particularly if there isn't any announcements!