Any time one has both substances (cocaine and alcohol) in their system at the same time, they’re likely to create some cocaethylene. So both the scenarios you describe would likely result in its formation.
And given the fact that cocaethylene is significantly more cardiotoxic than cocaine, both scenarios should be avoided if one has a low tolerance for sudden cardiac death. Early defibrillation is the treatment of choice for such sudden cardiac death, but even having an implanted defibrillator in situ does not completely guarantee successful resuscitation.
If one must consume both, I’d recommend at least 24 hours of alcohol abstinence before ingesting cocaine. Longer abstinence would be recommended if liver dysfunction, such as cirrhosis, is present. Like permanent abstinence.
Yes, it’s actually quite common because people (and I know plenty of them), found out they can drink a ton more than they usually do when they’re also doing coke. It’s stimulant effects make you not realize how drunk you are.
FWIW, I never saw anyone drink “call and ambulance” quantities. But were they would normally have 6-8 beers while at the bar, suddenly they realized they were on number 10 with a few shots mixed in and still feeling great (this is college, in Wisconsin). While a perk of the drug, it doesn’t help that coke makes you feel like a million bucks about 4 seconds after doing it.