If that were the case, then these circuits would never short out due to oil intrusion. There are 2 possible (one likely) mechanisms at play.Electronics 101
Current is a stream of charged particles moving through an electric conductor.
Because oil is a very poor conductor and the metal residue in the oil do not make contact with each other, there is no constant conductor for the charged particles to move through, therefore no current.
1 - metal particles in the oil infiltrate and accumulate in the sensor, and eventually short out the circuit. These can be an intermittent short (as the particles complete the circuit at times), becoming permanent over time as enough particles close the circuit or cause failure of the active components. This is by far the most likely mechnism.
2 - Enough particles are suspended in the oil to lower it's resistance to the point of interfering with the circuits. While I agree this is the less likely mechanism, I can't rule it out.