This is possible. Or maybe it's possible he got too drunk like he says, and doesn't remember what he did. That would mean his real "problem" is binge drinking. But how much of a problem can a guy have if he trains all the time, wins races, etc? How many days a year does he actually "party"? Are there reports of him being stark raving mad about town or doing crimes or being violent or anything?
I guess I can understand the perspective of people who are now sober after being junkies. But they should also understand the perspective of those of us who were quite able to use all sorts of drugs in our teens and 20s and did not become addicted or behave dangerously or become jerks or whatever and therefore did not need to do rehab or twelve step or any of that. In fact, this describes the experience of the majority of users: and yet the conversation is always dominated by the minority who couldn't handle it, and they believe their experience is the one everyone is going to have and therefore believe in zero tolerance. And since they themselves can't use casually, or even once, without falling into a deep pit of addiction and negative behavior, and the same goes for the peer group they find themselves surrounded by at treatment centers or AA meetings where they have to hear all the terrible stories of drug addicts, they equate drug use with terrible results, totally failing to realize their sample group is not representative of the real world. The vast majority of casual users will not end up as addicts requiring treatment.