Under "Selective Gear Rules" on page 13 of Washington Statewide General Definitions it is noted that "If any fish has swallowed the hook or is hooked in the gill, eye, or tongue, it should be kept if legal to do so."
I agree if you release the fish it has more than zero (as oppose to keeping it) percent chance of surviving but what is the logic behind this rule? and can you get in trouble IF you get caught?