No one is 100% wrong or 100% right in this case at it stands now, and reasoning that "the airline didn't really lose that much", "the DOT was putting the pressure on them", "the cost of flying additional passengers is close to nil", etc etc etc is just rhetoric because all of this is only relevant after the fact. This wasn't a 17% off deal, nor even a 50% off deal, this was apprx a 70% off deal in some cases.
The honest thing to do at-the-time, would have been to call El Al, but by no means should anyone have felt required. However, if you personally felt that calling them would have meant the deal would not be honored, than YOU personally should not have halachically booked the ticket.
Say your friend permits you to watch his house while he's out of town. For whatever reason your car won't start, and you know the keys to his car are in the house. You think about borrowing it and you justify to yourself that he would let you if he was here, so you don't feel obligated to ask! Well why not ask? Do you think he'll say no? If he won't say no, then why not ask anyway?
If the airline wanted to sell the tickets at that price, why not call them and book it? Because you think they won't honor the ticket?? Gosh, why would you ever get such an idea?
The issue here is really for people who KNEW the deal was probably bad but booked anyway. Justify it however you want, but if you had a doubt in your mind then that's you'er personal dilemma.
For those who were booking because the offer was there, and had no thought as to the legitimacy, it is definitely back on the responsibility of El Al's due diligence when conducting their business.
I really have nothing at stake in this argument I just think people are not realizing there are several different rationals to consider when judging the right or wrongs of this issue, and that people should not feel like they need to defend themselves for getting a ticket, or to attack those who did if they didn't get one. I think the fact alone that there's a divided "have" and "have-nots" is causing people to take the debate personally when there's no reason anyone should feel "attacked" ...
my 2 cents.