PJ2, I'm not trying to be right either, just trying to figure the puzzle out. Since I am also a B757/767 guy I don't know much about the A330 and how all that stuff works, just how airplanes in general fly and wonder why a pilot would zoom climb at high altitude into a deep stall.
I looked up the speed limitations of the A330 just now and see VMO is 330K and mach .86 is mach limit. They were cruising at about 280K and M.81 so the puzzle was with trapped pitot pressure and climbing 2500 ft what would the indicated mach speed be. I have no clue. I agree if they didn't change altitude nothing would change but they apparently did. When the CVR comes out I have a feeling the overspeed warning will be well heard in the background.