Here's how I see it, take it with a grain of salt...

If you are targeting steelhead, but are consistantly catching coho (out of season) you should change your methods. If you don't and continue to fish with the same lures, flies, presentation, etc, than you're targeting cohos and that's not right. C&R or not, you're going to have mortality.

As a side note, on another board I post on someone asked the WDFW if taking a picture of a fish caught out of season was illegal. A lawyer from the WDFW responded that taking a photo is considered "posession" and illegal under the law.