A company I worked for stated in the Ops Manual that never use Autopilot without A/T but that A/T without Autopilot was permissible at pilots discretion but had to be disconnected before touchdown. The approach into HKG on a dirty wet night was always interesting so keeping the A/T in until just around the corner could be a help if it didn't 'hunt' too much, I found.
Regarding the PPT accident I was under the impression that the lady co-pilot flying the approach did keep the A/T in and on touch down went to select reverse but missed a reverser or two, (possibly due to small hands), so as she pulled what she had in her hand back the 'loose' one moved forward and they swung sideways off the R/W, but that is only what I heard at the time.
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