"which does not allow them to eject customers for any reason whatsoever. The most circular thing they could eject him for was failure to follow the terms of the contract of carriage for refusing to disembark"
You should go back to law school. They can eject anyone at any time for any reason.
Both of your examples would violate Rule 21, H, 1, and therefore removal is allowed.
In the case under discussion, the passenger was not in breach of rule 21 for any of the listed reasons.