"He is acting too natural and deliberate. He is quite familiar with the place as well, to the point that he doesn't even need to search the place and walked straight up to the vault and very naturally showed his face like he didn't even notice the big surveillance camera on top."
"While he is inside the vault, it seems like he has gotten what he was after easily. That portrait painting should be covered by other stuff but from the way he went into the vault, removing other obstacles in front of the painting to taking it out of the vault, the whole process was within seconds."
"Unless the vault is very small, to the extent that it could only hold one to two treasures, but it wasn't possible. No one would build a vault just to hold one to two treasures. Even if one would really go so far as to protect the treasures, how valuable would the treasures be? If it is that priceless, why would the security be so minimal around the place, as if the place was almost empty of people?"
ITS A MERMAID!