Sounds like the oil pump is operating normally at this time. If the oil pump regulation went hay-wire and caused the filter to blow-out, it must have been a temporary situation.
As the oil temperature increases and the oil thins down, it takes more engine RPM to build enough pressure to open the spring operated pressure relief valve in the pump. I'm assuming this is an old fashioned, spring loaded pressure relief designed oil pump, and not a variable volume pump or computer controlled oil pump.
Yes, an unregulated positive displacement oil pump will try to cram all the output volume though whatever is connected to the output of the pump, and therefore the output pressure will get very high as the pump RPM and therefore the output volume increases.
If the pressure regulation valve in the pump was stuck closed at any level you would see some sign of abnormal oil pressure, especially when the oil is cold and the RPM up some ... that's when the pump pressure relieve valve would be activated the most.