Woman in ad who said a Democrat endangers kids pleaded guilty to endangering kids
(www.washingtonpost.com)
It's not a discrepancy, alcohol is processed over time. It's her body working through the stuff in the ~30 mins or so that it presumably took to get to booking her. Yeah we can assume the levels aren't 100% accurate but this tech is decades old so probably pretty close. There are many problems with policing; imo this isn't one of them.