I doubt I'd release a 15+ lb. trout even if it weren't a record.
This isn't any different than the dude that holds the world record (17 lbs. 7 oz.) It was caught on the east coast of Florida. He and his dad were fishing when he landed it. They both thought it was a snook.

They took it to a local store that had meat scales to "weight" it. When they were told it was a trout and that he had landed the world record....they used witnesses that (supposedly) saw the fish on the scales, took plenty of pics and it was certified. Luckily, the scales were "certified" scales. Here's the killer, tho...they ate the fish.