Didn't he just find/report a bug in the multi-gpu case? Then have a melt-down after an AMD engineer sent him a fix a couple of days later? I think you are overstating his contributions, in fact it's not clear to me he made any.
He shows the git patch fix delivered by AMD engineers. The root cause is not explained and the change itself is about 2-3 SLoC — his frustration, what you call meltdown, is not about the interaction with AMD rather how troublesome it was to get AMD’s demo scripts to run on AMD’s chips.
Feeling frustration about something not working is a normal part of software development. Reporting a bug, or choosing not to use that software are normal too. Making a public video trashing the work of 100s, using the language he did, is a meltdown.
I've worked on public software before, and it's left me with an extremely low opinion of this kind of behaviour, and the kind of people that show it.
Do you work at AMD and therefore have some kind of insight that we don't? Based on my own experience it's much more likely the call was just a marketing exercise, completely orthogonal to actual development.
Gfx drivers are complicated, long term projects. They're not something that get fixed with a phone call.
He found a bug, and made a bunch of noise about it. No need to make it more than it was.
