One of our profs at university called it the difference between drunken drivers and driving drunks. A drunken driver is just that, a person who consumed alcohol but still is driving a vehicle (which of course is dangerous and possibly fatal). A driving drunk is a professional alcoholic who just happens to be driving a car when caught.
If you have 0.3 (that's 2.37 ‰ for Germans, Swedes, etc; I had to google it) at 11 AM you are a driving drunk, not a drunken driver. If you are still able to operate a car at all with 0.3 you are a serious alcoholic. I hope for your friend that being caught and losing her job is rock bottom and a turning point for her, not just anther step on a downward spiral. 
Good way to distinguish them. Someone who is that drunk at 11 a.m., at work, is probably drunk much of the time. In fact, it's odd that nobody noticed it at work earlier, though I have another friend who works at the post office in a different city who had a coworker who frequently came to work drunk. Maybe the PO doesn't really crack down on that?
Her coworker eventually fell down the stairs in her home and died.
And someone who's drinking that much is on a dangerous path -- if not from stairs then from the effects of the alcohol itself.
I hope for your friend that being caught and losing her job is rock bottom and a turning point for her, not just anther step on a downward spiral.
I know. Seems like it could go either way, doesn't it? If she was already dealing with hard times, then the expense of the DWI, shame, possible jail time and job loss certainly won't make her feel better. But maybe she'll realize she needs help. Luckily she comes from a big family; hopefully they'll be supportive.
