There haven't been many lyricists in the past 40 years (outside of Sondheim and Lin-Manuel Miranda) who have delighted me as much as Alan J. Lerner. I look at Miranda's verbal brilliance and creativity first, I don't care if the rhymes aren't perfect (neither does he) or the grammar is not impeccable. These are not legal briefs or academic exercises. They are artistic expressions that are crafted like poetry. In any event, I wouldn't "excoriate" improper usage. I might make a note of it and question it but I would look at the piece in its entirety.