From the Operations log of No.74 Squadron RAF
Twelve Spitfire aircraft (6 of ‘A’ flt and 6 of ‘B’ flt) ordered to intercept enemy air raid which turned out to be a friendly formation of Hurricanes of No. 56 Squadron, North Weald. P/O BYRNE and a and P/O FREEBORN opened fire on two Hurricanes thinking they were Hostile Escort Fighters. Both Hurricanes were brought down. One pilot P/O HULTON-HARROP, was killed. Other pilot was uninjured. No enemy aircraft were sighted.
See TNA AIR 50/32
Byrne and Freeborn were subsequently acquitted of any wrong doing at a Court Martial held at Hendon on the 17th October. The record of proceedings at the Court Martial does not appear to have survived.
See also North Weald Airfield Museum.