What he gets no right to is the expectation that others will jump through a hoop he specifies when it is obviously detrimental to do so and no interest of there's.

One solution would be to have a general norm against offering vague criticisms without being prepared to back them up with concrete examples. If such a norm were in place, it wouldn't seem like you had made a concession to Wei in particular when you provided an example. You wouldn't have to "jump through a hoop he specifies", because the hoop would already have been pre-specified by the community. Wei would gain no status boost at your expense when you followed the general norm.

If such a norm doesn't already exist, do you agree that it should? If so, why not help to establish it by following it, while making it clear that you are providing the concrete example not because Wei requested it, but rather because there ought to be a general norm to provide such examples?