I pondered the same question on Jameson lake and others many times Carl.
That September October late season is primarily on spring fry plants that run
anywhere from 41/2" to 7" with a lot at 5-5 1/2".
I guess the answer is "Because they can" and because they don't know any
better place/way to fish.
That fella in the story had a legal limit of trout,but I'd still call it a moral violation.

The bigger question for a lake like Jameson is why the F&G doesen't close it
completely and let that fry plant grow to any size.
Relates to the question of why F&G doesen't close some lakes alternate years
so you baiters can get a less expensive larger trout than stocking pen reared
triploids at great expense.
Makes tooo good a sense I guess.