I don't think the author is going to think much about backstopping before shooting; I'm under the impression that the author is one of those who want to write about guns without knowing much about guns.It looks like he's getting ready to use a gun, but honestly I'd say it's dangerous enough to start shooting in a crowded place with onlookers in every direction. He should just pop their arms off.
He's going to need to deal with the guards who are apparently friendly with these guys too. Let's hope whatever scene he creates isn't so gruesome it would dissuade a guard to take the bandits' side. Then again, they might be daft and still decide to antagonise Daichi.