There are correlations in other faiths. There's a segment of the Christian population that is sometimes referred to as 'C&E Christians' (i.e., they show up at church for the Christmas and Easter services, but still follow the basic tenets, believe in the divinity of Christ, and so on.) There are Jewish people who only keep kosher during Passover.
Pointedly, the woman in question wasn't even drinking the alcohol, she was serving it - presumably to a non-Muslim. This would be akin to berating a Catholic from handing a non-Catholic a Big Mac on Good Friday. Or indeed, berating a Muslim from giving food to a non-Muslim during Ramadan (while they, themselves, fasted.) Do they expect all Muslims who work in restaurants to take the month off?