EXWOK ...well it was some time ago and my memory may not be what it was...
Anyway, pprune was not around then so the only rumour network speculating about such events was the local newspaper and the comments about the wind have stuck in my memory.
I wouldn't dismiss the Canterbury surface winds too lightly - they can and have caused a lot of damage especially to property and trees. Sitting in a 737 in a Nor'wester at Harewood at departure time can be a shaky experience.
However, I take your point about back driving a PFCU. Thinking about it, I would doubt that ground wind forces would come anywhere near the forces experienced in supersonic flight