With no apparent updates on the assailant of HMS Pink, U441 and U1191 I think being the two favorites, I looked further despite not having an accurate Grid Map, in to the incident apart from HMS Pink damaged on June 27th the following day the merchant ships, the Maid of Orleans was also torpedoed and sunk to the NE, followed on the 29th when another merchant Empire Portia suffered damage torpedo or mine [not clarified] again on a NE heading. The position U1191 is reported sunk on July 3rd, meant she was on a reverse SW heading from the last attack position, which ironically putting her close to where Pink was initially hit.
Looking at the position each U-boat now lies from where Pink was hit, taking in account of distance they had to sail, and with U441, sunk on June 30th had the greater distance to cover in only one day between the two positions. However, U1191 if she had hit Pink then continued on and attacked the two merchant ships, the last being on June 29th, she would have had longer [four] days to cover a shorter distance to the position where she would eventually be sunk. John