Wull ... Except it wasn't the sheriff that was off duty. They said it because the deputy, the guy who shot at the robbers, that'd be the robbers who had taken his (the deputy's) wallet and who had held up the store at gunpoint, the deputy was off duty. And it's important to mention that he was off duty because that meant he was probably not in uniform when they (the robbers) took his wallet (but not, apparently, his gun).