Sorry sport, handing them the warrant as you leave does not suffice legally.
The FBI is a pack of stinking liars. Their warrant was not legitimate, or they would’ve happily handed it over to his attorney as she stood there. Second of all, if they stuck to the scope of the warrant they would have no problem with the lawyer standing quietly observing them. It would’ve been a protection for them. The FBI lies and cannot be trusted. And then they do things like this which are precisely what someone with something to hide would do.
But the Stasi appreciates your support.