Bad conduct and dishonorable discharges can only be imposed by a court martial since it’s a punitive discharge. ADSEP can issue honorable, general, or other than honorable discharges. I don’t think that’s changed over time, but I could be wrong.
Also, I wonder if the appearance of unlawful command influence influenced the judge when determining the sentence, particularly the jail time. Not sure if the opinion is public. President Obama was found to have committed unlawful command influence when he “suggested” a punitive discharge to those guilty of sexual assault based crimes — the remedy was to not allow a punitive discharge to be adjudged in one particular case. There only needs to be an appearance of unlawful command influence, it doesn’t have to actually happen.