It's good that they made him understand the mistake in his actions.
Also, him atoning for it, because he never knew what he was doing was wrong, is a pretty good way to end this arc. It's not "just a sob story", it has some legit advice as well as some evident psychological problems.
To be honest, the boss should have been the one to go directly to jail and then sent to oblivion to always be forgotten, whilst the dude should be given help from a psychiatrist, with an adequate amount of jail time so he has time to atone for his actions.