In a standard MCI (e.g. train crash) you only perform CPR on a pulseless casualty if there are enough first-aiders *after* you have taken care of all the other life-threatening injuries. Common sense would dictate that you don't refuse to do CPR on casualty A in order to splint a broken arm on Casualty B, for example. But you would treat someone who was at risk for shock, or any other life-threatening injury, before worrying about a casualty who had no pulse.

The one exception to this, according to my training, was a mass lightning strike. The explanation was that casualties whose heart has been stopped by a lightning strike have a much better shot at recovery than someone whose heart has been stopped by trauma.

What the article is saying - and it sounds reasonable to me - is that in a mass lightning strike, shock, severe bleeding, and internal injuries are not likely to be a concern; therefore, given limited resources, the casualties you need to worry most about are those who (a) have a pulse but are not breathing; and (b) have no pulse and are not breathing. Both of those are life-threatening situations; the first takes precedence simply because they have a higher chance of survival.