Looking for chocolate

After they sent the captive Germans back to HQ, Robert Crisp and his friend Harry planned to search the German tank for chocolate. For some reason, the Germans seemed to receive an ample chocolate ration that was very welcome to the less-well supplied British. The Colonel congratulated Harry by radio and then ordered the two tanks to fall back to the 3rd RTR HQ. The seventh day was drawing to close, and the 3rd RTR Stuarts were widely scattered. They were being talked back to the HQ by radio. They could see small groups of tanks driving in to rejoin the 3rd RTR. When attacking the German transport column, some of the Stuarts had driven 10 miles from the start of the attack. The curious thing was that the German column had been unprotected. Why would that have happened, when there was usually a very good protection system? Robert says that later that night, they found out the answer to their question. This is based on the account in Robert Crisp's book Brazen Chariots.