Officer charged with filing false report resigns

The truth about this incident, as I was told. Correct me if im wrong.

The officer was a victim of identity theft. He completed the report himself. He asked a buddy to sign off on it because we are not allowed to sign our own reports. The other officer told him just to sign his name and turn it in which he did. Somehow it was found out that he signed his buddies name. When questioned the buddy claims to not have known the officer signed his name to the report (to avoid getting in trouble himself I would imagine). I know this officer and he is a good guy who had NO intention of committing any crime or doing anything wrong. He definitely does not deserve to be prosecuted for anything. This is another case of the administration heavy handing some officers while others get away with murder. He resigned because the department threatened him with prosecution if he didnt.