I know this is an old thread but it has brought up additional questions regarding MJ use and the FAA physical. Is a one time use of cannibis a disqualifier?

The way I'm reading the regulations (Part 67, neurologic here's the link): https://www.ecfr.gov/current/title-1...part-67#67.209

It says "No substance abuse within the preceding 2 years DEFINED as:" and then the four definitions are (I'm paraphrasing):

1. Use of substance in a situation in which that use was physically hazardous. So a one time use at home would not qualify?

2. positive drug result. (Assuming no test taken)

3. misuse of a substance that makes the person unable to perfrom duties going forward. Is a one time use considered "misuse"?

The reason I'm asking is because I know of a teenager interesting in flight training that does not use or abuse MJ or alcohol, but took a gummy one time during a bout of nausea, which was also his first time, and then never did it again. So this thread has me interested in this question.