Let me take a different approach to this.
I sometimes shudder at the meticulous, deliberate approach I see from many in Buddhism. Much more exacting than I could ever justify purely from a canon that was passed down by word of mouth for 500 years. This is NOT to say that any of the interpretations (like Nanavara Thera) are wrong - - just that their approach may be a little more exacting than is necessary.
Everyone appears to address this question from a perspective that in the west we call "criminal law". As a criminal defense attorney myself I have been dealing with these incidents for decades and the criminal justice system has hundreds of years and millions of cases further defining this concept we call intent (Cetana).
For example - the description of 4 factors necessary to violate the 5th precept written by Nanavera Thera. In the west this is what we call criminal intent and it is taught to attorneys attending post-graduate Law School. My point here is that we are unnecessarily exacting by going this deep. It's not nearly so complicated.
Are you an alcohol drinker? As a result of this incident would you now call yourself a consumer of alcohol? Remember the acorn. We are not defined by our condition at any given moment in our life. That is much too linear. If we ARE going to so label then at least do it by a predominant trait and not a singular incident. Thats the philosophical approach called "utility" and it's also the most rational. It's what we think of when we consider fundamental fairness.
You cannot live life being so exacting. It's all about balance. The lines defining either side are NOT clearly drawn - it's all gray instead of black or white. That's where we normally live. In the gray. So in the gray where the lines are vague we examine the entire context and not just one incident. Again I ask - are you a consumer of alcohol?
No. An accident does not make you a drinker of alcohol. Your guilt shows that immediately. If I wanted to control you I would say "but you should strive for perfection". Thats not my intent though. My intent is to relieve your concerns and remove the trouble from your mind. See how I almost took that another direction? Intent matters and we get it from context. Keep striving. The path is a hard one.