At 16.50 hours on 31 Jan 1942 the German blockade runner Spreewald was hit by one torpedo from U-333 and sunk by a coup de grâce at 18.33 hours. Cremer had spotted an unescorted and zigzagging steamer and examined it from 400 metres distance before firing his second last torpedo, but he could not identify the Spreewald as own ship because she was camouflaged as Norwegian Elg and after the first hit they sent an open emergency call with the name Britanny. The German ship was ahead of schedule and transported 86 prisoners from ships that had been sunk by the German raider Kormoran.
The Spreewald had been awaited by U-575 (Heydemann), which should have escorted her to France and by U-123 (Hardegen), which had an injured crewman on board who should have been transferred to the ship. These two U-boats and U-333 began to search the area for survivors and were soon joined by U-701 (Degen) and U-582 (Schulte), which were returning from their patrols and U-332 (Liebe) and U-105 (Schuch), which just had begun their patrols. Five Fw200 Condor aircraft from France also searched the area, but the most U-boats were low on fuel and had to abort their search soon.
In the evening on 2 February, U-105 found 25 crew members and 55 prisoners in three lifeboats and three rafts and took them on board. They reported that another lifeboat, containing the master, ten crew members and 13 prisoners had become separated, but it was not found during the search, which continued the next three days. Schuch then took course on Lorient and reported that he had a severly injured German sailor on board. A Dornier Do24 flying boat was sent out to pick him up, but it made a crash landing due to rough seas. The U-boat rescued the seven crewmen, sank the wreck with gunfire and finally arrived at Lorient on 8 February.

Cremer was court-martialled immediately after returning from patrol, but after he had the possibility to explain his mistake and an analyse of the situation, it was decided that he was not guilty.