What a horrible click-bait title. There is nothing about a C185 or one modified with a STOL kit that is unstallable. A better title would be something like "Clueless pilot stalls aircraft. Which unfortunately is not an uncommon thing.
> However, the investigation discovered that despite his experience, he had never practised stall recovery on the Cessna 185. The pilot had no knowledge of the aircraft’s stall behaviour at all. His opinion was that the Cessna 185 simply didn’t stall.
In writing targeted at lay readers, I would expect this to be followed with something like "This opinion, of course, is complete lunacy. All aircraft can stall. Practicing stall recovery should be a normal part of pilot training."