They clearly over-generalized. I didn't say they "overstated." They didn't say "in some parts of Seattle" they said "in Seattle."
I'm sure there have been edge cases in every state of the country where the power has been 10 days at someone's house because of unique circumstances. That doesn't meaningfully change the risk profile of a heat pump over gas furnaces.
It wasn't a unique case. It happens about once every 20 years. The time before the 10 day event it was 4 days. I live in the middle of the Seattle metropolitan area, not out in the country. The powerlines were down for miles around. The powerlines thread through the trees, and the trees fall on them during a windstorm.