Unless the robber showed some indication that he was about to shoot, either at the customer or at the clerk, the customer should not have drawn his gun. He could have been killed or could have killed or seriously wounded an innocent person. Even so, and even if he is exonerated by the state, he could still face a wrongful death lawsuit if he was not directly threatened. It could be argued that no one was in danger until the customer argued with the robber and then drew a gun.

Even police officers will not take a chance on opening fire under those circumstances for those reasons.

Jim