I am not sure it is a bug or an error, but in Serpent's Crown there is a Paladin, a Shieldbearer whom can train you, provided you pay his fee. This fee implies joining the order, per the Shieldbearer's words but... my character *is* a Shieldbearer as well and I'd got an option to acknowledge the fact to which this trainer responds positively, but still I am charged to join the order to get the training.
I don't have a problem having to pay, ability points be Ability points and all that, but the text still mentions me having to join the order and I have no other alternative than to agree or not.
I could see the trainer parsing this as a cost for time/materials or even to help the order, but not to join it (again)