My understanding is they have to be released by the family. I would doubt a button could, most likely a skipper would have to authorise his release.
This doesn't preclude associates from different families working together on jobs, but when you're on record, you're on record.
MORGAN: Why didn't you fight him at the park if you wanted to? I'm not goin' now, I'm eatin' my snack. CHUCKIE: Morgan, Let's go. MORGAN: I'm serious Chuckie, I ain't goin'. WILL: So don't go.