I never said that it was. But the ship was sunk by a German submarine, the U-862, operating out of Penang, commanded by one Heinrich Timm. That is documented historical fact.
https://uboat.net/allies/merchants/ship/3400.html
https://uboat.net/boats/patrols/u862.html
Right, it is fascinating to learn about the Monsoon Gruppe, never heard of it before.
Your sources say there were a total of 41 German U-boats sent to join the Monsoon Gruppe in George Town, Penang, on the Northwest coast of Malaysia, but most never made it, sunk by Allies on the way.
U-862 (Type IXD2, long range) was a particularly lucky boat, or well-captained, take your pick.
She avoided sinking by her own rogue torpedo, shot down an Allied PBY and escaped the resulting search for her.
She sank seven allied transport ships, including the Robert Walker and another, the only Allied ships sunk by German U-boats in the Pacific.
After Germany's surrender, U-852 became Japan's I-502, surrendered at war's end then scuttled in 1946.
None of U-852's crew were wounded or killed.
Some eventually returned to Germany, others remained in Wales, Britain, after the war.