I found this piece of info
In addition to the 5 crews that failed to return, there was a further fatality. Sgt John Butterworth, mid-upper gunner of LL902/EM-A (F/O Eric Oakes) was killed in an attack by two nightfighters and is buried in Manchester Southern Cemetery; the aircraft returned safely with the rest of the crew, including were the late Association members George Chesworth and Derek Brundle (uncle of the motor racing tv commentator Martin Brundle).
As a result of the attacks on the 4th/5th and 7th/8th July a total of 92 downed aircrew were on the run in northern France, of whom 52 successfully evaded.
Just as a point of interest I live in Manchester and not far from Southern Cemetery, I will see if I can visit his grave, take a photo and see what other information is available.
Rest in peace Sgt Butterworth and thank you for your service