The potato (a wet thing) was in a pot (contains steam, if covered. Unclear if you covered the pot or not, but the fact that you mention a pot implies a cover, as opposed to a baking tray/pan/sheet.) With a cover, the potato would be essentially oven-steamed. Without a cover, baked at very low temperature.
Nothing carbonizes at 80 °C - certainly not potatoes. Some things become unpleasant to eat if cooked that hot, but they don't carbonize. Time to unlearn some incorrect knowledge by the power of actual experiment. Flabbergast whoever taught you that, it was in error.
Typical baking temperatures for potatoes (or "oven fries" if looking for "without skin" information) are MUCH higher, and the potatoes do not turn to charcoal, even a little bit, unless ignored for an excessively long time. 200 °C on the lower end of typical (at a longer time) for skin-on whole potatoes, 230 °C on the higher end of typical and when attempting to achieve "fried" with an oven (where heat transfer is rather slow compared to oil.)
Deep-fried (in oil) potatoes are typically fried (which transfers heat much more quickly to the surface layers) at 185-190 °C. More usually first at a lower temperature, rested, then finished at that temperature. They will burn if ignored too long on a much shorter timescale.