You don't say if the G1000 is gas, lp or diesel.
With a diesel its possible for the oil to be burning and 'going away' and not be noticed in the exhaust.
Usually the hydraulics leak into the engine because of the pressure differential between the hydraulic pump and the crankcase. That's not good either, hydraulic fluid does not work well as an engine lubricant. That happened on Dad's Farmall Cub and wiped out the rings.