wrote:
[...] he could give a crap less
what anyone thinks of him and just says what he feels without having
the need to justify it.

Looks like a fallacy, specifically: special pleading:

Why is that justification considered valid when applied to an anonymous
poster like Bertie but not valid when applied to a poster who uses his real
name like Jay?

As far as I can tell Jay has just as much right to "give a crap less what
anyone thinks of him" and just say what he feels about "Bertie" without
having to justify it.