Agree with the above. Trash fish (generally speaking fish from the Sucker and Minnow families) don't get a lot of love from trout anglers, or on this site, but they do serve a purpose and should be respected in their own right.
In my experience, almost without exception (I can't think of any as I type this anyway), small freestone streams that have either Chubs or Fallfish, or both, generally produce larger wild trout than do streams that are trout only. This may be in part because in extremely high gradient (and often acidic) headwater streams, Brookies are the only "catchable" size fish capable of inhabiting them, but in lower gradient, small freestoners where there's Chubs or Fallfish, there's bigger wild trout. Doesn't seem to be a coincidence IMO, and doesn't seem to matter if it's Brookies or Browns either.
I know they're not pretty to look at, but Fallfish are very aggressive and good fighters...good fun on a 4 or 5 wt, or UL spinning rod. The shame in what you saw nealfish was that whoever caught that sucker probably had a lot of fun fighting it until he/she saw what it was - assuming it was caught and thrown on the bank by an angler of course. Could always have died during higher flows and been left on the bank as the water receded too. But I'm sure that kind of stuff does go on unfortunately. You hear similar tales of sub-legal wild trout getting mishandled around opening day by guys looking to harvest stockies and thinking that the PFBC stocked "shorties."