You can see the benefit Roberts is getting from his time there in this game. Aberdeen are the only team to press Celtic so hard in the league, in their last game even though Celtic scored a flurry of goals early on Aberdeen gave them a horrid time.
In this game Roberts is getting panicky, because Celtic need to score to win this Cup, and he is getting the experience of the pressure to win a Cup final. It's a great experience that very few of our loanees will be getting in such a pressured environment.