The legal issue is unlawful "take." The form of take that tossing a salmon fin to a seal could be is "harassment." NMFS has to prove that this action constitutes harassment. The downside is that the courts generally defer to the agency's technical expertise. The upside for Tom is that the only difference between what he did and when a seal takes a salmon from a fishing line or from a gillnet or eats the innards tossed overboard when cleaning a fish is that tossing the fin to the seal was deliberate and not coincidental, as the other actions are. So there is uncertainty in the outcome.