Here are the appropriate rules. I would let the fish go if the fin is intact even if it seems stunted.

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Chapter 220-16 WAC - DEFINITIONS
WAC 220-16-470 Wild.
"Wild" when used to describe the difference between a hatchery fish and a nonhatchery fish means a fish with all fins intact. A fish missing an adipose or ventral fin with a healed scar at the site is not a wild fish.


Chapter 220-56 WAC - PERSONAL-USE FISHERY
WAC 220-56-100 Definitions -- Personal-use fishing.
The following definitions apply to personal use fishing in Titles 220 and232 WAC:
(11) "Hatchery" when used to describe the difference between a hatchery fish and a nonhatchery fish means a fish missing an adipose fin or a ventral fin with a healed scar at the location of the missing fin
(28) "Wild" when used to describe the difference between a hatchery fish and a nonhatchery fish means a fish with all fins intact.
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To my mind a partially clipped fin with a healed scar is not intact but on the other hand a partially clipped fin is hard to consider as being missing. My thought is that the code should be ammended to account for partially clipped fins.