I'm sorry, but I'm not that impressed so far with your source's research at the AFHRA/RS when they say;
"347 FG has no AVC for Jun 1943."
AND...my previous link shows an award of the "Distinguished Service Cross" of the engagement on 16 June 1943 and the pilot being assigned to the 339th Fighter Squadron under the 347th Fighter Group. So I don't understand why that would not have come up.
I would ask for a search of the 13th AAF and the 18th Fighter Group Gen Orders for June 1943 without using an Order Number. Might add in the 8th Fighter Group just for grins as that still has possibilities. The number we have could have a typo or any other number of things wrong. I would think the Silver Star would have to come from the higher HQ's such as the 13th AAF and not the Group or Squadron level, but I could be wrong.