Giving anyone Karma after a thread went 'wrong' is an action of taking sides...whether it's the 'right' side or not makes no difference.
Taking sides, whether actual or just in token form [karma] continues the confrontation/whatever that ultimately led to meltdown.
If a thread is closed it SHOULD be closed.
And that would ideally include posts from people who still had the page open AFTER it was closed/locked and thus ran the roadblock.
I know that would be problematic...but at least Karma can be stopped.
It is clearly UNFAIR to only allow Karma be given to the 'good guys' and not the cause/s of the closure....so the only 'right' thing to do is bar it...