The 8 hr "bottle to throttle" yardstick is now way out of date and far too vague.
Flying alchohol-in-bloodstream limits are much lower than they were only a few years ago.
london-flyer's friend should report her concerns to her management IMMEDIATELY and, failing action being taken, to the applicable Civil Aviation Authority. It would be her duty to convey her suspicions to airport security upon report for each day of work with said pilot. This should all be possible anonymously with a bit of prior thought; if it is'nt then the system needs to be changed in that country.
The guy possibly needs help, but more importantly, he must be grounded until he's assesed to be OK or not. Mistaken accusation is better than dead passengers, crew and innocents on the ground.
IMHO