Massive oil leaks.

As was said - if it was blown by the fan it was not coming out the breather - it was coming out somewhere from the front. Oil pressure has zero to do with crankcase pressure. Ring seal and gaskets have to do with crankcase pressure.
Personally I'd want to run the PCV, or I'd be running twin breathers but if everything is kosher it should be ok with only the one provided it's working properly. Did you pull that breather off and look at it? I've found plenty of those cheapo chromee ones to have the stamping that lets gasses pass through the nipple open a little so very little can pass. Take a screw driver and open that "flap" up a little more and make sure the non-cut part of that flap faces down when the breather's installed (or it will drip).