They are talking about the mouth of the green on the toutle, not the mouth of the toutle on the cowlitz. But, my thoughts exactly. I caught a chrome bright silver last week that looked almost like a steelhead. I had a hard time telling the difference and I've caught alot of both. The way I figured it out was my fish had a slight hook to the nose and it was a hen. We released a fish earlier that we were not sure about and I've released fish on 2 other occasions that I presume were silvers, but was not sure and did not want to handle a fish for an extended period of time that may be released.

Now back to the topic, Its hard to say if it was a steelhead or not from across the river, but that really is irrelevant, because it is wild coho release and this guy should have known the rules or at the very least handled the fish with care until he found out. I'd give the guy a break though if I mishandled a fish that I had to release and it didn't make it. I would not only feel bad about it. I would learn from it.
I saw a guy at the mouth of the Toutle 2 weeks ago land a dark 35-40# king. His buddy drug it up onto the ash/sand with the hook of his cane through its gills never touched the fish. Then they admired it in the sand for what seemed like five minutes before picking it up and attempting to revive and release it. I saw them push it off and did not see it float away but I cannot see how it could have survived.