My doctor told me to cut down on drinking? Was he right?

Random one! I had blood tests the other day as I’d had to tonsillitis for over a month, by this point it had cleared up but thought best to check. It was my friends birthday the night before and we all went out for some drinks, nothing heavy was in bed by 9:30. Blood test results came back and he said I had enlarged blood cells but that I had had them since 2009. He asked if I drink regularly I said no not really. He then said at the end of the appointment I should cut down drinking. I’m confused why he would say this? Do you think it’s because I had drinks the night before? I know large blood cells can be caused by alcohol but if I’ve had this since 2009, surely it would have been flagged before?! Don’t know if I’m overthinking or if there are any doctors/nurses that can share insight! Thank you ☺️