Now see I am willing to risk a bit more. I have a puffer in my reef tank(temporarily, but he is going to be there for a couple months). Now I will not so foolishly put a starfish in here, but I do have corals, other fish, snails (getting fewer everyday need to buy more

), hermit crabs (I did NOT invite them, they came with the LR and my puffer is not eating them argh!), worms,
feather dusters large and small, sponges, etc. You get the idea.
I don't consider him not reef safe but I don't consider him completely reef safe either. He is okay CONDITIONALLY in a reef setting like 90% of the fish that are available to the saltwater aquarist. His conditions are this, he eats crustaceans and may not be safe with some soft flesh invertebrates. Some fish have conditions like not with less aggressive fish, no corals, etc.
There are very few fish that can be safely kept in a full reef setting, and equally few that can't have any type of reef system in their tank.