OSCAR
Let's examine your suggestion. The aircraft was in ALTCRZ in which it is linked to Altitude in Alt window and when disturbed from it will try to get back to it by climbing or descending while VS0 is not linked to any altitude but V/S zero. If disturbed by updraft as was the case AC will deviate and try to maintain VS0 where ever it stabilises. So it is less aggressive. But in the present situation when the ALT mode is unable to prevent climb or descend changing to VS mode will cause larger deviations. Yes it may give you better ride because it accepts deviations. I don't see any magic solution in VS0. The pilot applied the correct procedure but may be he could have left the AP on till it disconnected on its own. It may have handled it better but not VS0.