Caiman are the most commonly kept "pet" crocodiians. There is a subspecies called dwarf caiman which are often just sold as caiman. So that might be what this is. They are often kept is very large aquariums or "ponds" (those big black hard plastic pond liners commonly meant for coi).
I think the guy will get hosed in the end because caiman are crocodiles. But the search and seizure was by definition illegal itself so at the very least he would get some restitution. But I don't see him getting it back.
People need to know their rights and the law. Animal "cops" are actually cops at all. They have to have a real cop with them and a warrant to search for andf seize an animal with the exception being an animal in distress of which they have to have evidence of.