Wow, pretty snake. I'd have a hard time killing that snake just to back a bow. For that matter, I have let quite a few bull snakes get away, too.
Prettiest snake job I ever saw was a gaboon viper backed over osage orange. Gaboon's are not too common on the prairies of South Dakota for that matter, so I don't think they have to worry about me snagging their coats (well, they being one of the 5 deadliest snakes in the world may have something to do with that, too).