How did Juggernaut still have his helmet while he was in prison? When he escapes, he has his helmet on. I can’t believe they would have just let him keep it on while there, or would bring it with them during the transport. Was there any explanation of how/why he still had it?
It probably falls under "personal effects" which by law have to be housed and transported with inmates in most jurisdictions so they're available immediately when the person is released.
As his armor is magnetic, they probably used human tech to bring him in, and had no need to risk their lives removing his helmet.