Not risky at all IMO, if the fish dies then it's nutrients are recycled back into the food chain.
In order to survive a significant injury a fish has to become a highly motivated and successful eating machine, this highly aggressive eating pattern will likely be carried forward once it has healed completely.
In the short term an injured fish won't grow as it heals, but it is likely to make up some of that growth once it has. All that is needed is a good forage base and time. It would not surprise me to catch this very same SMB again in the next four weeks, if I do I will post pictures here showing how it is healing. I suspect that four weeks from now you won't be able to see where the GBH hit it.
Last edited by Shorty; 04/21/14 08:21 AM.