Depends on the numbers and worth keeping an eye on because at first sight with Dneg at 12/1 and some excellent unknown online players at 33/1 stars don't know their arse from their elbow in pricing this.
He is 12/1 because they will lay him large at that price. Wouldn't surprise me even at 12/1 he will be the biggest loser in the book even though he is prob a true 50/1 shot. No point laying 25/1 if you can lay him at 12/1. Good bookmaking IMO.
Red armi has probably priced it up as he works there now.