Pretty sure liver damage isn’t a side effect of phenylephrine—it’s a side effect of Tylenol/acetaminophen/paracetamol, which is often but not always included with it in combination cold medicines (some include ibuprofen instead, or no painkiller at all). Tylenol might have been present in what this nurse was buying, but it’s also possible that it wasn’t. Phenylephrine’s main side effect is high blood pressure, I think—my father’s forbidden from taking it for that reason.
We have no reason to believe the nurse’s family were taking all of each package. Someone in the family could be pitching out half-empty boxes as “no longer needed”, or just forgetting where they put the stuff and then discovering it’s past its best-before date when they find it later.
Equally, they might have four kids and all of them plus the parents getting the same cold sequentially as they pass it from one to the other. 7 days per cold x 3 doses per day x 6 people = 126 pills. Two colds per year would then require 8 boxes of around 30 pills, but no one will have taken them for more than a week at a time, or more than two weeks in the year. That isn’t chronic use.
As for buying it for relatives outside her own household, it isn’t hard to sketch out a scenario: “Ugh, I’m (achoo!) dying here, sis—can you stop off on the way home from work and get me something for this? You’re a nurse, so you’d know better than I do which ones work.”
(Yeah, I’m playing devil’s advocate a bit here—I have no more real information than you do. My point is that while the media may have cherry-picked their example, this person isn’t necessarily lying or doing anything dangerous.)