Yeah, the guy sounds like a crazy jerk but hunting or teasing him on social media is just adding more assholes to the formula.
Human beings really, really hate "taking the L," though. And I include myself in this.
To be fair, in my experience, there's very little incentive to do this in real life. Much like saying "I don't know", saying "I was wrong" has way too often a worse payout than either doubling down on errors or simply moving on quietly.
Social media is particular in that it's very public and asynchronous, leaving your mistakes for anyone and everyone to scrutinize. If fewer people can see your mistakes for a shorter time, you're a lot less at a risk of being caught. On the other hand, admitting to being wrong or not knowing makes it instantly very visible.
I think people just naturally transitioned to social media and kept this intuitive approach that traditionally works, except the framework isn't the same at all.
(This is obviously less true for people used to publishing or making public statements)