Is this even possible???

I'd clean it all off again real good as stated above. Then Monitor the situation. It's not normal but anything is possible. In Theory, a cracked Head or Blown Gasket could possibly push oil through a Head Bolt. Kind of like the Perfect storm Scenario. Chances are there would be other symptoms. Just keep a close eye on it. and Check for any related symptoms. Such as Oil/Water mixing or Blow by or oil on spark plugs. Don't ever underestimate the ability of oil to blow backwards from somewhere "Up Front" on the engine. Timing cover Bolts could leak for instance and oil could Migrate back there. I'm not trying to freak you out I'm just saying to check everything. If you prove 100% that the head bolts are leaking then it would have to be a crack or Bad gasket.