Peter makes no claim as to what people choose to do or why they choose to do it. Regardless, people’s beliefs are irrelevant to the question of whether alcohol consumption is beneficial.

Peter only cites “recent evidence”, never appealing to any popular belief.

Peter’s conclusion is simply that alcohol consumption is beneficial, so it doesn’t matter if there are other methods that are too. His flaw is assuming that alcohol consumption in general has net-positive effects just because moderate drinking has certain limited benefits.

This describes how Peter’s evidence is too limited for the conclusion he draws. The evidence only suggests that “moderate alcohol consumption” has certain benefits, yet his conclusion is about alcohol consumption in general.

Peter actually does consider this since he acknowledges that the beneficial effects impact certain bacteria. The flaw is assuming that these benefits outweigh any potential negatives to heavier drinking.