[beagle3]

I do not know Chicago Law, but he likely didn't violate it. He might have violated federal law, but that enforcement has to be done differently afaik. Chicago Police was almost surely in the wrong, and United was in the wrong for calling them.

While one (especially United) might expect this to make no difference, the letter of the law is what should have been followed in this case.

Police often tend to make up nonexistent laws as they go. Those imiganiry laws might even sometimes make sense. But "with great power comes great responsibility" and that responsibility is to only uphold the laws on the books.