Cammer, what master caster did is plain and simply wrong, this isnt a personal decision its actually the law.
Base on the provincial regs:
It is illegal too:
Waste the fish you catch. If your fish is not suitable for eating or if possession is illegal because of
quotas, size limits or closed seasons, return the fish quickly and gently to the water.
In terms of you point regarding hatchery brood, IMO any offspring whether from hatchery or wild parents are better than not having any offspring at all.
I know the game wardens south of the boarder would have strung a guy up for something like this and in fact, I don't think it say much for the guide that he didn't A) himself understand the regs or B) explain them to the fisher.