I'm not aware of any non-destructive tests... But if you are prepared to sacrifice the first couple of images on the suspect roll, you could always cut the film where you expect frame #1 or #2 to be. Should be fairly easy if you use a developed (but not cut) film as reference. According to Murphy you will of course split a frame when cutting.... For a very Q&D test just put a little piece of film (not the leader, as it is already exposed) in a little cup with developer, and develop for a few minutes. If the film is exposed you will see it when the lights come on. You might save some money, but not much time...