Does anyone have the answer about what happened at 300' to increase the V/S.
Do you know that final report was already compiled, it answers this and other questions? The report is fairly compact, easy read, I suggest you grab it. Pilots indeed disconnected autopilot at about 550' and from that point were flying manually. Yes, this was VOR-DME approach flown autopilot-coupled in LNAV/VNAV mode up to point when A/P was disconnected. I don't think you can answer 'why' a pilot pushed the yoke, you can only register that he did.