When Geoffery threatens Max and Kimble with a revolver belonging to Max it was a Smith & Wesson model 10 .38 caliber revolver with a four inch barrel. However earlier when Ellen removed the case from the desk drawer and opened it to find the revolver missing the interior of the case was fitted for a snub nosed revolver with only an approximately two to two and one half inch barrel. It would have been impossible for the gun Geoffery was brandishing to have fit in this case.
At the start of the program, Geoffrey stops playing, pulling his bow away from his violin, yet the violin continues to sound, clearly revealing that the Rex Thompson is merely pretending (acting) to play, and that the music is being put on the film at a later time (and synchronized badly at that!).