I just wonder if the robo umps/challenge system got in his head. Stark article from last week confirmed that MLB moved the top of the zone down 2 inches this season as part of their experiment. This has let hitters like Cave and Hall prosper by looking for pitches to hit in a small part of the strike zone.
For someone like McGarry who lives on the high strike his reaction might be to try to be too perfect. Which then results in walks or hard hit balls because being perfect (i.e. Nola/Wheeler type of command) is just not in Griff's skillset.
I don't think he is hurt, but I probably would be careful with him and manage him on short outings the rest of the way and shut him down if things get messy. There is a reason they keep adding AAA arms for the AAA postseason.