I've always believed the Nazis started the fire, then blamed a lone Dutch "communist" for it. The Gleiwitz incident, called Operation Himmler was carried out by Abwehr and SS forces on August 31st, 1939 and was another Hitler false flag, in order to invade Poland, which he did the next day, September 1, 1939.
Nazi operatives dressed up in Polish military uniforms, took over a radio station in Gleiwitz station and broadcast a short anti-German message in Polish.
"To make the attack seem more convincing, the Gestapo executed Franciszek Honiok, a 43-year-old unmarried Upper Silesian Catholic farmer, known for sympathizing with the Poles. He had been arrested the previous day by the Gestapo and dressed to look like a saboteur, then rendered unconscious by an injection of drugs, then killed by gunshot wounds. Honiok was left dead at the scene so that he appeared to have been killed while attacking the station."
Not going to write a treatise here, but short version is your belief is absolutely correct. In fact, it's been proven beyond a shadow of a doubt.