If you have the male necropsied it won't be able to tell you if a pathogen was involved, most likely, but it may be able to tell you if it was some sort of physical malformation. Maybe his heart was bad, maybe his kidneys shut down.
It doesn't sound like you've got anything running through your snakes, but it's hard to know with such limited information.
I'd keep on as you're doing but if nothing else goes bad in the next couple of weeks I'd go ahead and breed what's ready.