There seems to be only two ways coolant can get into the oil and if it is not homogenised it could be the oil cooler. When guys store their bikes for the winter some leave the old oil in and it is very acidic, it attacks oil coolers, even gearboxes, you cant just turn the bike off and walk away for six months, deadly mistake. Very easy thing to do is take the oil cooler off and pressure test it. This is easier than checking the head gasket. Get a new oil cooler gasket before you remove it.
The coolant pump has a little hole where it joins the engine to stop coolant getting into the crankcase, doubt if this is blocked.