The situation in your video should never happen. The switch dog that was hanging at the edge of the cam detent is the motor 1C switch stack. That switch stack contains the motor runout switch. The runout switch ensures that the motor will run until the switch dog in question drops into the cam detent. That is the home position for the motor and it must always stop there. The fact that this was not happening indicates that your 1C runout switch is not working.
The runout switch is the set of contacts closest to the cam. You need to clean and adjust these contacts so that the motor runs back to the home position any time that the 1C switch stack is out of the cam detent. Otherwise you will continue to have "gremlin" problems with your game that will come and go and will be very annoying. For example, if you happen to turn off or unplug the game while the motor is running, you will not be able to get it to start up again using the replay button because the motor will be stuck in the non-home position.
If cleaning and adjusting the runout switch doesn't cause the motor to always return to the home position, then check the wiring to the runout switch.
As for the position of the switch dogs, they should all be in the "S" position (the slot closest to the switch mounting screws) except for the dog at the 2C motor position, which should be in the "L" position (the slot farther from the switch mounting screws).