I think most hit TV shows are sued at one point or another by someone who claims to have actually created the show. Usually it's someone unknown, but once in a while you get a real producer or writer with several credits who claims to have created the show. This is one of those cases.

Anthony Spinner, who among other credits produced and/or wrote for The Man From U.N.C.L.E., Cannon, Search,The FBI, Return of the Saint, and Baretta, is suing both ABC and Touchstone Television, saying that he created (and was paid $30,000 for) a show that is very similar to Lost way back in 1977. He actually sued back in 2005 but the case was dismissed for procedural reasons.