That happened to me a few times (35mm) accidentally, and the results were horrible each and every time. Came out way underexposed, and very dark bluish/greenish, and splotchy. Not even sure if the film won't disintegrate later. Note: film was Portra 160 and the rolls were processed to completion in standard (XTOL I think) b&w chemistry. I did not discard the developer later, but probably should have.