Imagine a self proclaimed driving instructor from England - obsessive and deaf - constantly preaching to continental students to drive on the left side. *
> I believe it would be correct to point out present mistakes in the node,
These corrections bind more energy than feeding all the other trolls together, because you can't leave them uncommented.
Just have a look at Worst Nodes of The Year ²
And the proportion of his negative posts is astronomic. ³
> however I do not think it is correct to just let bad blood flow in this forum.
A lot has been said and proposed already, even automatically marking or reaping exceptionally negative posts.
But if you think "some of the points ... are in fact valid" you are welcome to put your energy into discussing them.
*) well imagine a Brexiter "politician" giving all his jingoistic speeches in public in Europe ...
²) now try to imagine worst nodes of the last years.
³) almost one quarter of his posts are negative, far more have been down-voted at least once.
It's obvious that almost everybody is relieved when he doesn't show up and practically nobody would miss him.