My alcohol ravaged brain causes me to disremember exactly the layout of the Huey Engine Oil System....but if it used a wet bulb sensor for temperature after the cooler in the return line....an absence of flow of oil might yield inaccurate or unusual indications contrary to the actual temperature.
The absence of oil over the bulb would also create an issue as it is measuring the temperature of the air or structure touching the bulb and not the oil.
Knowing the normal indications and being attuned to being to changes from normal temps or other unusal indications is important.
Gullible is right...a single indication is of some concern....two or more are of real concern.