I did not see Hart adapting to Peps system against Arsenal.
Neither did Caballero against Dortmund. Atleast 3-4 times he passed straight to opposition forwards in pre-season and the Sunderland match. Caballero (no better than Hart) is staying but a club legend and England No.1 is leaving. It's hard to take that when he hasn't been given enough opportunity and time to adapt.