In the hallway with Jess, Nick is wearing a button-down shirt on top of a long-sleeve shirt. When Jess runs into her room and Nick goes after her, he enters the room and the button-down has disappeared.
There is no such thing as a California lionfish. Lionfish are native to the South Pacific and Indian oceans. Also they are not protected and a popular aquarium fish. And a clown fish is not fresh water as Schmidt called it.