There will always be some oil residue in the PCV side tube, as it is the primary draw of crankcase gasses and oil vapors to the intake manifold, and quite frequently in the "clean side" tube that goes from the valve cover to the intake body before the throttle body. Normally, the clean side just supplies clean air from the intake to the valve cover to compensate for PCV side being drawn into intake manifold. But under some conditions, like full power WOT events, there can be a draw backwards of CC gasses thru the clean air side. That can oil up the clean side tube a little. This occurs with new engines as well as old worn engines.
All of this is the primary motivation that some install oil filtration "catch cans" on the PCV side, and check valve equipped clean side oil separators.