@ Climber
This doesn't look like classic "runaway trim".
It looks like erratic unwanted trim that I can reverse when I use the switch on the yoke, And then 5 seconds later the damned thing trims down again.
So if the trim would have continued down the instant I released that switch I would have claimed "runaway trim" and gone thru the procedure. That 5 second delay would puzzle me. Not sure about the previous flight cockpit conversation, but looks like they had a few minutes to decide on "runway trim" procedure, take action and fly to the destination.
It is a good bet that any crew following the "runaway trim" procedure right away would have made it back to the airport, just like the previous crew. But the symptoms do not seem clear, and the new MCAS may not have been briefed or flown in a sim.
Gums...