Here it is, plain and simple. There are 9 Federal prohibitors. They are:

1) Under indictment for or has been convicted in any court of a crime punishable by imprisonment for a term exceeding one year;
2)Is a fugitive from justice;
3)Is an unlawful user of or addicted to any controlled substance.
4)Has been adjudicated as a mental defective or has been commited to any mental institution;
5)Is an alien illegally or unlwfully in the United States;
6)Has been discharged from the Armed Forces under dishonorable conditions;
7)Who, having been a citizen of the United States, has renounced citizenship;
8)Is subject to a court order that restrains such person from harassing, staking, or threatening an intimate partner or person;
9)Has been convicted of a misdemeanor crime of domestic violence.

Argue what you will, but he had marijuana, has an open case in court concerning marijuana and has admitted using marijuana. If it looks like a duck, quacks like a duck....