Player is able to ride and tame trader llamas

What I expected to happen...:

What I expected to happen was that the trader llama was going to be untamable and stuck on the Wandering Villager's lead.

What actually happened...:

What actually happened was that the trader llama was off of his lead and was tamable. 

Steps to Reproduce:

1. Put a trader llama in a minecart.

2. Push the minecart very far away from the Wandering Villager.

3. Get the trader llama out of the minecart.

4. Right-click the trade llama until it is tamed.