I'll caveat my post with: I eat just about anything, I've never ordered a special meal on a plane.
My family, (and myself in the past) have worked in hospitality / catering, and certainly take dietary requirements very seriously.
I respect dietary requirements without prejudice and feel that if you're in a service industry, if someone makes a dietary request, it should be treated as being for an allergy, rather than a preference.
If an airline offers a specific meal then the pax should get what they select.
I agree with this. I'd also lean toward the interpretation that special meals are there to cater for people who have dietary
requirements more than just preferences. e.g. the above discussion about gelatin not being vegetarian - if someone has a religious dietary restriction the mis-labelling could be quite serious for them, or if someone is allergic to eggs, as an example.
I have always ordered VLML (lacto-ovo veggie) and always get VGML (vegan): this is completely different and not what i want to eat.
While I completely understand that while you may be OK eating eggs and dairy- a VLML
may contain eggs or dairy. A VGML is still VLML compliant, it just doesn't have eggs or dairy in it. It's not hard to make something that's vegan and still tastes good (whether the catering company does or not, that's another story).
For a domestic, short flight, I think it's perfectly reasonable for an airline or catering company to work out the most efficient way of solving all the special meal requests. It might not be to your preference, and it still should be nutritious, but as long as it (in your case) doesn't contain meat, I'd say they've satisfied the requirement. (In my opinion).
I do however think that if you order a VLML, whether or not what you get contains eggs or dairy products, it should be labelled VLML, and not VGML, if it happens to be the same "vegan clag" that's served to those who ordered a VGML, that's another story...
Just my two cents...