Seriously, there’s often no absolutely clear answer on this – sometimes all you can do is make the best judgement you can and use it as your basis for making decisions. When I try to be fair, by default, I am relying on my definition of what is and isn’t fair. I can’t rely on anybody elses.
The nature of the punishment is irrelevant. As you say – Fairness is what counts. An unfairly imposed “telling off” is no more fair than a caning. I don’t know about you (or Bob T) but I would resent any unfair punishment. .
A point I’ve just made myself. I didn’t make it in the original posting to Bob because I can’t make every single point every time I post even if some people seem to think I should.