What you’ve done here is a criminal act according to the CFAA, and your exploration of their site could also be construed as wire fraud. As you’ve done this across state lines this is also a federal felony. You’re also in violation of the GLBA, as you’re disclosing the availability of airline customer information. You could also fall foul of the FTC and the wiretap act.
I have seen people (Weev, Michael Brown, numerous others) go to prison for similar, and this lot could win you years in a federal penitentiary.
Please, consider the legal consequences this could bring upon you.
I would simply forget about it and promptly delete this - it’s their problem, not yours, and by posting about it here, they could decide to make it your problem.