Looks like a fine trip.
Sorry to hear about your fall. Glad you are okay.
Williamson's chute is very loose. It's pretty treacherous even if you pay attention: years back I was descending that chute with some climbing partners after making the summit. We were tired, but careful, as we picked our way back to the bowl we staggered ourselves to avoid knocking crud onto each other. Near the bottom of the face, I slipped on a sandy patch and simply slid onto my bum (no big tumble) when the weirdest thing happened. When I slipped a small cascade of sand started but it built and built over three seconds before eroding sand from beneath a microwave-sized boulder, which dislodged. I cried out "rock!" even though my buddy below was well off to the side. We were stunned when the boulder did one leisurely, slow roll down a sandy runnel smacking an embedded stone and glancing off at a higher speed. The rock changed direction down a steeper talus bed, hopping and pin-wheeling faster in a sloppy line towards my partner below. Fortunately, since I had called rock (even though it was obligatory and unconcerned at first) we had all stopped and paid attention. My buddy below had seen the change in direction and was on his toes the second the boulder careened towards him. He was bouncing up and down like a runner at the blocks as it wasn't clear if he needed to move. One final bounce of the boulder sent the boulder hurdling squarely at his chest. He dove out of the way with a little over a foot to spare. We all sat there for a moment grateful we had been careful, paid attention, and staggered ourselves. It took everyone doing stuff right to avoid disaster.
A buddy of mine recently was severely injured up in the Evolution region. Be safe out there!
