Yes, he had timing problems in an online tournament on chess.com (against a Mexican GM in the same room) where his computer did not have all Windows updates and/or the timezone was wrong.
You're surprised that Kramnik is mentioned when the discussion topic is related to chess? I don't understand why. He's well-known in chess (and in chess memeland).
Kramnik is a former world champion who has taken a torch to his own reputation by accusing tons of people of cheating without evidence. He’s been banned as a regular columnist on chess.com after using his column as a platform to attack people. He has next to no credibility on any chess issues these days.
I think there is difference between "accusing tons of people" and "using his column as a platform to attack people" vs "accusing that one person in one instance".
It is actually perfectly fine to not ban people doing something wrong one or two times while banning people doing that exact thing for fifth time.
No, the difference is between a well connected mob going after a single person (Niemann) vs. a single person going after several.
The former is always excused, presumably because people's ancient group instincts kick in. The latter is a single heretic that must be destroyed.
The group does much more damage than the individual. Everyone already thought that Kramnik's pseudo-mathematical evidence was garbage, so why the ban? The answer is that he mentioned well connected people like Nakamura, so the rogue nail needed to be hammered in.
Groups are never punished, and 95% of Internet commenters always excuse the group.
chess.com confirmed the issue.