He had some time, but he did not use that time to accomplish the necessary task. By the time his sights first fell on the robber, his gun should have been ready, round chamber (Israeli draw). The time it would take for the robber to redirect his gun and fire (if it was loaded)at Merrell (with his gun drawn and pointing at the robber) is significantly faster than Merrell can respond to the movement, rack the slide, and fire. Merrell pointed a gun at the robber and made demands at a time when Merrell's gun would not fire. At that moment, he was basically bluffing with his own life on the line. That was not a very bright thing to do.