Fatalities happen basically from: product stacking combination medicines people don't realize contain acetaminophen and/or multi-day accumulation exceeding max daily limit over multiple days.
Chronic drinkers have impaired acetaminophen processing so they can't handle otherwise safe doses, but fatalities still typically occur in multi-day accumulation scenarios. Their safe daily max is ~half that of a non drinker.
The effects of one round of acute drinking don't impair the liver in the same way. People are not dropping dead because they took a normal dose of acetaminophen for a hangover. Not that I'm recommending you start doing it, but it is a myth.