Actually rain and fog on Whistler is not all that uncommon. While it normally has huge amounts of snow all season making it one of the most consistently snowy ski resorts in Canada, it's also a very temperate mountain. It is know for a lot of milder weather for a big mountain but it usually has enough snow endure.

Vancouver , if you take yearly average, has the warmest average temperature of all of Canadian cities and is also known as one of the rainiest. Victoria BC, being the wettest if I remember right. (I'm on the opposite coast.)

Whistler/Blackcomb and surrounding mountains 'should' have been a very safe bet for having lots of snow for the Olympic games but rain and fog should be no surprise.

With great power comes Awesome irresponsibility.