A dirty air filter can cause oil to be pulled past the seal ring on the compressor side. Plugged or insufficient crank case vents can cause oil to be pushed past the seal rings on both the compressor and turbine sides of the turbo.
No running or standing oil, just an oily film all over everything. I will say the air filter is FILTHY and I should get a new one as I don't think it's even worth trying to clean it.