I believe this is a bug and not sure if redstone knows. If you are using image doctor and searching for a large image the discrepency search usually takes a while. While the search is still looking if you choose action Recapture image eggplant freezes and does not respond then you must force quit.
We’re aware of some hangs when using the image doctor. I’m not convinced that you have to force quit; the app usually comes back in 30 seconds or less, although if you’re looking for a large image, it could well be longer. The more tolerant searches can take quite a while to process a large image. We have these issues resolved for a future release (date undetermined.)