It sounds like something may be wrong with your engine's oil scavenge system that returns oil to the tank from the engine. This goes through the filter on the tank, so it could explain why the filter is dry. Under normal operation the scavenge system operates all the time, including when cold. So the filter shouldn't be dry. But it ran 10+ minutes like this? That isn't believable to be honest. If oil weren't being returned to the tank, its contents would be used up in less than 10 minutes.
I'd suggest some diagnosis to figure out what's going on with the scavenge system causing it to operate inefficiently.
Here's a post showing a 911 oil system for reference
http://forums.pelicanparts.com/porsche-911-technical-forum/145705-oil-system-drawing.html