I think there is a large difference between using a frying pan that has been washed, and eating food that is has been cooked in meat juices.
@SlowSigh That's true and I agree with you but that's also not what you said when I was replying to you.
You said that if people are fine with cross contamination then they are not vegetarian or vegan.
My point is that there are degrees of cross contamination and different people have different thresholds.
And I'm not totally convinced that "cooked in meat juices" is what's even happening here. Again there's a big difference between flame grilling meat at one end of a grill and a veggie burger at the other, compared to basting something in meat juice.
I'm on a few different vegan forums and the majority opinion seems to be that most people consider it acceptable, because they already acknowledge that most restaurants will have some degree of cross contamination and that supporting the availability of non meat alternatives is largely a good thing.
There's also a pretty pervasive feeling among many vegans that this "not really vegetarian" outcry is pretty much just yet another "gotcha" aimed at vegans in an attempt to undermine veganism as a whole. This whole shared grill storm in a teacup already played out across the pond and didn't really work.
People love to play the "hypocrite vegans" whataboutism card or try to undermine the rising market for plant based alternatives. The right wing press is particularly adept at creating these non-stories.