Thik about it this way:
Measure the fish.
Measure the distance he fell.
calculate the number of body lengths that he fell.
Think about how you would feel if you fell that number of body lengths. The differential in momentum allows the fish to survive. But i'm sure you wouldn't be yourself for a few days.
If consequence dictate my course of action, then it doesn't matter what's right, it's only wrong if you get caught.....