He is not wrong. I quote from the Supra owners manual page 94:
Oil consumption: Max 1.0L per 1000KM
When judging the amount of oil consumption, note the oil may become diluted and make it difficult to judge the true level accurately.
As an example, if a vehicle is used for repeated short trips, and consumes a normal amount of oil, the dipstick may not show any drop in the oil level at all, even after 1000KM or more. This is because the oil is gradually becoming diluted with fuel or moisture making it appear that the oil level has not changed.
The diluting ingredients evaporate out when the vehicle is then driven at high speeds, as on an expressway, making it appear that oil is excessively consumed after driving at high speeds.