The coho in the Cap should all be zombies by now, this might be why you're having mixed results. If that guy caught a fresh one, he was very lucky.
Generally, how long do salmon stay bright in a river? I agree that few if any fresh Coho are coming into the Capilano. However, I have some thoughts? The Cap is a very small system with extreme water level fluctuations, many deep pools, and very cold water. Because of these factors, I theorize that some fish can come later, hold longer, and stay fresh longer.
The coho season apparently runs through December, so I feel that some fish may still be entering and holding throughout...just not in great numbers. And because, there is little pressure right now, I still think that chances are reasonably fair.