Stirling was not captured in an ambush but was caught napping by a German patrol that entered the wadi while his unit had hidden up to rest for the day. For some reason they had not set up a guard and Stirling was kicked awake by the German unit's dentist, who took him in to custody.
The German tank that ambushes Stirling, Cooper and Sadler is not Panzer II, III nor IV that the Germans were using in Africa, but rather a Cold War era American tank, presumably M-60.