Every Lav must have an ashtray or somewhere to extinguish lit cigarettes. It's part of FA safety checks every time they board a new a/c.
Smoking on flights happens much more often than it should, but it sounds like the crew handled it well in this case.
It depends on the length of the flight, but my pours get weaker and/or my refills take longer after the 4th drink or so. UA FAs use the stoplight system for determining when to cut someone off. It's not inconceivable that someone got to 6 J&Cs.