First off, he wasn't hacked, he was phished. No one took something directly from someone's wallet. Basically the guy gave it to them once he fell for their trick. He even admitted he fell for it by clicking on a marketplace that he trusted to be real.

Also, no one "froze" any asset. The assets are still in whatever wallet owns the keys. What OpenSea did was freeze the ability to trade it. Just most people don't know how to do anything with them without a tool like OpenSea.

Your example really doesn't illustrate the point you are trying to make.