I often have problems on flights with getting vegetarian meals/snacks. I get a feeling that vegetarians are treated as exceptions and are either denied food or given leftovers. This happens on many airlines, even if you have ordered your food preference and paid for it a long time in advance. The crew on board claims innocence.
To cite a specific experience, I was once travelling from India (Hyderabad) to Australia (Brisbane) via Singapore, by Singapore Airlines. I got vegetarian food on the Hyderabad to Singapore flight (he shorter one) without any fuss, but on the Singapore to Brisbane flight, the crew said this was not possible.
After I made a big fuss, and even produced my ticket printout with my registered request, the steward relented and offered to provide one vegetarian meal for the two of us. When I complained, they produced vegetarian meals for both of us.
Is there any legal action possible for such lapses?