(In the UK this is described at 3.6 units per glass, or about 7 units per day. Safe limits for men are not more than 3 to 4 units per day, not every day.)
Or it could be 2 glasses, at 150 ml per glass, of a 10% ABV wine. That would be 1.5 units per glass, or 3 units per day.
A "serving" of alcohol is considered 0.6 fl oz, or 14 grams, of ethanol. People tend to overestimate what constitutes a "serving" of any food/drink, with consequences in line with the withdraw effects he experienced.
Not in the UK!
I think this is largely an academic discussion. Some people drink a glass a wine every day, some people binge drink once/two times a week. If you consider alcoholism to be the point at which you can't withdraw without death resulting then both groups will pass. If you consider regular alcohol consumption as a potential psychiatric problem then both groups are suspect. But both groups still have:
A) People who just drink socially/for fun.
B) People who are alcohol dependant (in terms of a psychological crutch).
This brings back the crux of those who argue such subjects: some people are the "a glass with dinner" type and experience almost no effect, some people are the "six-pack at a time" type and experience significant effect, and very few in either category seem able to acknowledge the other category exists at all. Their average may be comparable, but frequency * intensity produce wildly differing results.