Vegetarianism is about what you eat not what you wear.
There is obviously a possible contradiction depending on why the person is vegetarian, but if it is for ethical reasons then it's about how much a person contributes to animal suffering etc. So even if they do wear leather shoes compared...
I'm pretty sure they do have other things that they worry about.
Why is someone a **** because they don't want to use products that have animal byproducts in them?