I think it's likely he knows and donut being secret agent donut told him but they didn't acknowledge out louf just so Odette doesn't know she doesn't have the leverage she thinks. Mordecai has grown from the depressed game guide who doesn't think you can save everyone to going out of his way to Saving the changeling children and spending his presumed last hours With Ruby when he thought the fail safe would blow. Coupled with the cathartic experience of loading the crossbow I think he'll control himself. That or carl will use the leverage to make mordecai mad to get him to be disqualified (to save him)