Yes indeed. Not to mention distressing for them. wouldn't have been your fault of course, but if I were served a chicken samosa insted of a veg one, I'd be somewhat upset.
I used to buy veggie samosa most week from a Farmers Market. I haven't bought any since they gave us 5 meat instead of veg. and i saw her take them from the box that said veg. We are vegetarians, so I still cringe when I think about nearly eating it!
Thankfully, when I did serve a vegetarian friend some samosas from the same source, they were indeed vegetable. If I ever again serve samosas from that source to a vegetarian, I'll have to very discreetly and carefully open them up and look inside to avoid any embarrassment - and have good alternative vegetarian food available in case it's needed...
MinL once bought a fruit pie and it was meat!