Thoma is known for his indiscretion while a POW in British captivity, when he unwittingly revealed the existence of the V-1 flying bomb and the V-2 weapons programmes.

He was subject to surveillance by British intelligence and while speaking to another German officer, was recorded discussing rockets that were being tested at Kummersdorf West, which he had observed while on a visit that also included Generalfeldmarschall Walther von Brauchitsch, the Commander-in-Chief of the Army.

British reconnaissance flights over Peenemünde Army Research Center in May and June 1943 brought back unmistakable images of rockets at the facility; the subsequent bombing of the site severely disrupted the programme.

[1] During the Spanish Civil War, and now a colonel, he commanded the ground element of the Condor Legion, following the German intervention on the side of the Nationalists under Francisco Franco.

He commanded tanks in the field during the Battle of France and was intended to hold a senior role in Operation Sealion, the planned invasion of Britain.

[8] Trent Park held high-ranking enemy officers prisoner in comfortable, but secretly monitored, conditions.

While there Thoma was recorded speaking to another POW, General Ludwig Crüwell discussing rockets that were being tested at Kummersdorf West, which he had observed while on a visit that also included Field Marshal Walther von Brauchitsch, the Commander-in-Chief of the Army and other technical programme details.

[10] Trent Park also intercepted, when he stated that "every bomb, every piece of material and every human life that is still wasted in this senseless war, (is) too bad (German: zu schade).

Liddell Hart, who interviewed him after the war, said that Thoma was "the most famous of the original German tank leaders next to Guderian":A tough but likeable type, he is obviously a born enthusiast who lives in a world of tanks, loves fighting for the zest of it, but would fight without ill-feeling, respecting any worthy opponent.

The advent of the tank in warfare was a godsend to such a man, giving him a chance to re-live the part of the mail-clad knight.