When Zorro is holding Captin Love at bay, he tells his guards to face the window, with one behind the other, and bend over. Zorro then kicks them out the window. The slipup is that he kicks them out one behind the other, but the come out side by side. They may have been able to be partically next to each other, but not perfectly even.
I saw this last night. The guards ARE side-by-side. When Zorro stops the guards, one is slightly ahead and to the right of the other. This is evident when Zorro tells them to turn left and bend over. But what is a slipup is he kicks once and both crash out of the window at the same time.