I don't necessarily think this is bullying or humiliating, but it's silly to think that being done by a "bot" and being "factual" has anything to do with it. If a malware "bot" secretly posted people's porn viewing history to their facebook page, would that not be humiliating for those people? Or would it not because it was factual and done by a "bot"? Clearly it would be.
Saying it was done by a bot is no excuse for anything. The bot didn't spontaneously pop into existence - somebody created it and decided what behavior it would have.
In this particular case, whoever created the bot could easily have made it email the authors of the mistaken papers and given them a chance to correct the mistakes before outing everybody in public.
Being done by a bot is not an excuse in general. However, when pointing out objective factual mistakes, I think there is a difference between your colleague pointing it out, and an automated tool pointing it out. Even if result is the same, the former can be embarrassing, hence why we learn to phrase negative responses in a roundabout way. But politeness cannot be expected of a brainless machine, and so it can deliver simple facts.
So it seems that it boils down to public disclosure before private?
Out of curiosity, how would you imagine the "correct the mistakes" procedure after private disclosure? The author cannot just edit the paper, it's already published. They would have to publish errata, which draws just as much attention. And, from an ethical perspective, if an author is notified of a mistake found by autonomous tool, wouldn't they be required to disclose the methodology when publishing errata? So I'm not sure how that whole situation is fundamentally different from just dumping it in the public.
Saying it was done by a bot is no excuse for anything. The bot didn't spontaneously pop into existence - somebody created it and decided what behavior it would have.
In this particular case, whoever created the bot could easily have made it email the authors of the mistaken papers and given them a chance to correct the mistakes before outing everybody in public.