From my limited understanding of the transcript, it reads as though the aircraft encountered wind shear during the go around, whether annunciated or crew detected. It appears that the autopilot was then disconnected, presumably manually, to fly through the shear. This is probably an automatic response to training, as I suspect many operators do not routinely teach the autopilot coupled escape manoeuvre.
If the aircraft is for some reason grossly out of trim, this will have been masked by the autopilot, and the out of trim condition only apparent on disconnection. Assuming that the trim is for nose down, it would explain the pitch over. This will almost certainly have come as a surprise to the crew, but the "Don't worry, don't worry" sounds like it could be the captain, and indicates to me he has recognised a problem and at this moment feels it is something he can control. The subsequent CVR transcript of "Don't do this" I'm pretty sure is directed at the aircraft and would suggest that the aircraft is not responding as expected.
Why they couldn't recover, only further investigation will tell.