I believe you nailed it. I pushed it hard on the way up there — 2400RPM at 34” and was at 23,000ft. Engine monitor data showed a drop in oil pressure about a half hour before landing. I didn’t see it as my workload was concentrated on the accumulation of ice I was experiencing through the descent and the JPI didn’t alert me to oil pressure dropping below the green as the red doesn’t start until 10psi. I’m somewhat annoyed at this as it loves to flash all sorts of warnings that don’t matter and aren’t placarded in operating limitations, such as RPM over 2500, or mp over 35”, et cetera, yet doesn’t fucking say anything when the 0.1” high numbers under oil pressure drops below the green arc. Pulled intake filter. Turbo is toast. Ordered remanufactured turbo, checked compression, bore scoped, checked dipstick tube pressure and inspected oil filter for metal. All is well except for the turbo. Will fly for 10 hours and check filter again for metal once new turbo is installed.