Oil temp goes up when turkey breast is added - why?
Where does the temperature readout come from?

I would be very curious indeed about the results of measuring the temperature with a thermometer directly in the oil.

As far as I know there is no exothermal chemical reaction between meat and oil, so adding a colder piece of meat to hot oil should ALWAYS reduce the temperature of the total volume (assuming that no extra heat is added from an external source)