"he edits a well regarded and nominally more radical media outlet that many sane and intelligent people turn to. (OK, we know this is not the case) So whether we like it or not, I have to treat him as a journalist...
Taking criticism on board would indeed be part of his role were he a genuine journalist. Unfortunately Tisdall is merely a propagandist which makes fact and truth his enemies.
I reckon most "sane and intelligent" people pay no attention to the Guardian anymore...a hollowed out shell now filled with a poisoned centre: it pretty much went the same way as the Labour Party.