I saw somewhere that he received an honorable discharge. That's not consistent with being booted out. So I looked it up and found this:
Micah Xavier Johnson. He was an Army reservist who spent seven months in Afghanistan from November 2013 to July 2014. During his deployment, he was accused of sexually harassing a fellow soldier, which resulted in a restraining order and mental health counseling. The Army wanted to dishonorably discharge him, but after some twists and turns he received an honorable discharge in 2014.
Protective coloration?
Probably. That, and it's just easier and quicker for commanders to administrativley "chapter" a dirtbag out of the Army than it is to go through formal UCMJ proceedings.