@maxelly
I'd eat it, but then my reasons for vegetarianism are to do with environmentalism not finding meat or fish repellent per se, so as long as no extra animal was being used in my food I wouldn't be bothered about any 'contamination'. But plenty of people find any animal product disgusting in itself so I guess they'd say no, people's reasons for not eating meat vary quite substantially...
I was just about to comment something similar to this.
I would eat it, but I am the world crappiest veggie, so it seems. My reasons are environmental too. Therefore, when making food choices I will always choose veggie/vegan options - however today, my DP was going to throw half a beef burger away..I was starving and thinking of the environmental impact of food waste drove me insane, so I ended up eating it.
I think levels of vegetarianism/veganism are very personal to the persons reasons and beliefs for choosing eat a certain way.
You cannot really judge if your son is being "fussy" by your own standards.
Many vegans/veggies would shoot me down totally for eating half a burger, but inline for my reasons for not choosing to eat meat - the waste of a dead animal - when i was hungry- being thrown in the bin, didn't sit right with me.
The burger would have been thrown, I would have ate something else, thus putting more pressure on the whole flawed waste system. Makes me a rubbish veggie, but I have my personal reasons. The same as your son has his.