One difference is, and George has come right out and said it, he doesn't care about anyone outside of the WKPP. Your and my acceptance or rejection of DIR is not going to make a bit of difference to him because his life and the life of other members of the WKPP do not count on us in any way.
If someone wants to listen and learn, they will. If they want to fight, he doesn't want to deal with them. He'll make an example of them by slamming them and exposing how and where they're wrong, but it's not for the edification of the party slammed... he considers them to be a write-off... it's to show others who are interested how screwed up thinking, overthinking, or poor planning, can result in problems.
As director of the WKPP (prior to Casey's turn at the helm) his word was law (as is Casey's). He didn't need to fight people. He didn't allow "this" or "that", and anyone who insisted or argued was off the team. This was protection for the team members... not to promote his ego. There are ways to introduce a different idea, and there are ways NOT to do it. Showing up for a dive with a "surprise" is one of the ways not to do it, but he IS open to suggestions... check out the BAUE website where they discuss introducing an alternative argon mounting method.
The internet persona is the culmination of over 10 years of dealing with people who question, then question again, or challenge, after being given a clear answer. My patience would run a little thin as well.
This is covered in a slightly different manner on disk 3 of the DVD set in the interview section.