There was some discussion about this at an inspectors meeting focusing on equipment of 1200 amps that was less than 6 feet in width and also a room with several 800 amp panels next to each other.
It was concluded that based on the Code less than six foot wide did not require the two exits. It was also concluded that a single piece of equipment had to be 1200 amps or more.
I would not want to be in the room under either of those situations when their was a catastophic failure without a second way out. Especially if I had to stop and turn a door knob.
Alan--
