Nef
Your "Polish" sources seems almost word by word to have been lifted from Fighters over Tunisia by Shores, Ring and Hess
This book is pretty old by now and not 100% reliable since more data has become available later, BUT it is still an excellent start and a trend setter how books should be written.
I think however Shores is wrong when saying that Hackl claimed one B-17 shot down and a probable. IF he did, it is not mentioned in Prien's JG 77 volume III. Instead Prien states that Heinz Bär claimed TWO B-17s. This then makes the total claims of shot down Fortresses the same.
Leo
According to Hess (the American in the trio) the Yanks lost one B-17 and six P-38s that day. Two of these were lost from a "straggling" mission flown by the 82nd FG, who very well could have been dragged into this fight. As usual nothing much is known about their damaged aeroplanes...
As a aside, the number of claims made by the US bomber gunners were in all 24 destroyed, 12 probables and 9 damaged which gives a good indication that this was a tough fight indeed. Many has mocked the gunners of these bombers for their inaccurate claims, but I would like to see anyone on this list crawl into position and have some 50 fighters charging in firing REAL shells and bullets right on YOU and not being scared to h..l ! These overclaims were a clear reaction of the intensity of the fighting, and those guys deserved every claim they could get, true or not.
To go out in a bomber and especially having just to sit there and just take it took real guts and I think every one of us would have chosen fighters instead of bombers (IF we had had any choise that is...

)!!
Cheers
Stig