Obviously, I'm in no position to disagree with someone of Joel's background on a subject like the cause of cravings (!), but when I read this, I wanted to offer up an alternative theory for why this woman encountered a craving in the ice cream isle.
My thought is that ice cream, particularly chocolate ice cream, causes truckloads of endorphins to be released into the system. Many of us have a strong desire to eat ice cream as we walk down the ice cream isle - a result of marketing and the body's own recollection of the endorphin releases from burying a spoonful of chocolatey goodness into one's mouth.
I would suggest, Joel, that it is possible that your friend wanted to buy and eat ice cream, and that the nicotine craving that she had may have been triggered by this having been her first time addressing the fact that she a) wanted an ice cream endorphin boost, b) couldn't have it until she purchased the ice cream and got it home, and therefore c) had the urge to tie herself over with nicotine until she could get to the ice cream.
As to the increased duration of the craving, I would suggest that it is possible that seeing the ice cream, wanting the ice cream, denying herself the ice cream and not being able to smoke her way through it in the store could cause one craving, and that leaving the store (a common trigger on its own) after having suffered through an ordeal inside the store (less common) may have triggered a second craving, as smoking after an ordeal is pretty habitual.
This is an alternate suggestion - might well be wrong
P.S. I'm hitting five months without nicotine this weekend thanks to this site, this community, Joel's commitment to helping people and my understanding (finally) that the way to beat this addiction is to know that at any given point in time, I may be called upon without warning to go five minutes without allowing nicotine to enter my body. Never take another puff!