Did he just get lazy??

With victory in the air, Flag made the decision to return to the Mansion immediately.  Perhaps she realized there was no food at the summit, or she just got lonely.

Half way down the hill, she ran into Pinkerton.  He raised his tail to acknowledge her accomplishment, but refused to look her in the eye.

What kind of a Hillside Warrior skulks away from a challenge, then tries to join in the celebration walk?

The Pinkerton kind, that's who!