I've heard you can still drink while breastfeeding, but you have to pump and dump or at least wait an hour for 1 beer to clear your system. But that's just what I've heard.
When breastfeeding, whatever you put in your body you are feeding to baby. I don't see an issue with ONE beer. Def wouldn't do it regularly. But it would be the same as ppl that drink soda while breastfeeding or eating lots of sugar. You want to be as healthy as you can for you and your baby. I don't like to have regret so I play it safe.
I personally would never risk it. I would pump and dump. But in the article you mentioned, the woman claimed to have only had two beers, not one on top of the other but with a bit of a gap, and food too to minimize the effects. But the waitress that turned her in claimed she was sure the woman had three or four empty glasses in front of her that looked like mixers.