Women cheat for thousands or reasons like men too.
The thing that this woman cheated him with a taller guy doesn't mean that height was the reason, moreover as the guy who was cheated was 5.10,5 which is solid average and a very respectable height.
So doing LL for that reason, which is probably only in the mind of the friend who did this thread and not tbe real reason for the girl to cheat on him, is truly nonsense.
I've been dumbed too from my ex and sometimes she told some a little funny things about my height but first of all I am 1.74 and not 1.78 and most of all I don't think it was the real reason I've been dumped as the other guy was much worse than me in every aspect except height (he was about 1.81) and she used to tell me that I am much better looking than him.
So, if I was average height or a little more I wouldn't care if a girl cheated me with a taller guy because then height doesn't matter and after all girls most of the times don't cheat due to appearance issues but other mental things they have in their weird mind. Now I want to do LL because I am less than average in my country and that bothers me and I know that with 6cm more I would look much better, not for my ex or any other specific girl.
So doing LL for an ex or a specific woman who maybe has a height fetish when you are completely average is a very bad idea imo.