I included Broadhurst's account of this incident in my book 'Luftwaffe Losses over Northumberland & Durham' (Pen & Sword Books, 2002.) Broadhurst did not see the He111 crash. He pursued it when it dived '..vertically into low cloud, its downward plunge marked by a trail of billowing smoke..' and he was very close to the sea when he broke through the cloud base. There was no sign of the bomber and Broadhurst assumed that it had crashed into the sea. His claim was subsequently substantiated by land-based observers. I could not find a record of the loss in the Luftwaffe Loss Returns for the period around that date and thus could not provide details of unit and crew. The book 'Blitz,then & now' vol.1 (Battle of Britain Prints International,1987) claims that the He111 belonged to Stab/KG26 but Rudi Schmidt's history of KG26 ('Achtung - Torpedos Los! [Bernard & Graefe Verlag, 1991] ) records no loss by KG26 for this date. If you would like a copy of the account in 'Luftwaffe Losses...' let me know.
Bill Norman
(
www.billnorman.co.uk)