Kevin - on the large res pic it looks like an easier way around to the right and is that a cairn on the bench to the right? Is that where you went up and down?
Good spotting. I know about 10 or so people who have been up Willingdon. All, including Pierre and I, stayed as per the route description and stayed on the crest of the West Ridge all the way to the summit cliff band. In the photo, just left of the snow patches, towards the low point in the band.
I also spotted the weakness you mention, the gully to the right, with the thin snow patch tending left. I did mention it, but we decided to the stay the course up the West Ridge crest.
That gully probably goes since the south ridge from the summit is written up as very easy. Since we were "on a mission" we stayed with the standard ascent route.