If I may, this is not an airline issue. It is entirely common that companies that offer catering have rules regarding employees taking food. It is entirely commonplace, that when someone "lifts" some food unathorised, sometime with extremely sound purpose, some asswipe jobesworth will shop them, because that's what asswipe jobsworths do.
Off the top of my head I can think of three instances I have personally witnessed...
A PT in a gym, took an orange...and gave it to a customer!!...sacked.
A burgerflipper, took a burger and gave it free to mate...sacked.
A team of department store fitters, took some dried up food, past midnight, because they had been left nothing to eat, on an all night job. Not sacked because a director stepped in and offered to sack the fkn jobsworth who reported them instead.
That's the greedy, sucky, profits-for-the-board, fkd up world we live in now.
And judging by democracy's latest finest hour, it's world a lot of people are happy to live in.