l have now been able to check through the books that I have here. No mention of any shoot-down. I can find four Sunderland losses in the area during the Korean conflict:

Two, from 209 Sqn (PP164 & RN277), were due to damage during typhoons whilst anchored in Japanese bases.

One. PP148 (88 Sqn), was lost during a landing on heavy seas at Iwakuni.

The last, also from 88 Sqn (RN302), was lost off Tsushima Island, Japan, when one engine caught fire and another lost power. It forcelanded at sea and was scuttled.

Like Pondskater, I would be interested in learning more of the incident related in the first post.