This stuff is simple. Cheating your way into the lounge may be morally wrong to most (all?) people, but it's so trivial law-wise and causes such a negligible damage to the airline that it wouldn't even waste the headed paper required to produce a nasty letter (unless it was a daily occurence or something). Assume they wanted to sue you...under English law (and unless there's some obscure exception somewhere) they are not entitled to punitive damages...will they file a claim for 2 bacon baps and a glass of Bolly?