Hi
No. 416 (RCAF) Squadron flying Spitfire XVIs had a bad experience with "Friendly Fire" on 24th December 1944, when US Army AA fire at MALMEDY opened fire on their formation, shooting down two and causing three others to crash land. One pilot, F/O J R Beasley being killed.
The following day another 416 Squadron patrol near MALMEDY lost another Spitfire XVI to "Friendly Fire" this time to a USAAF P-47, the pilot F/O A G Borland being killed. On the same day No. 439 Squadron flying Typhoons were also attacked by the USAAF this time P-51s, however, they avoided getting damaged (out flew the P-51s?).
On a wider perspective the 2nd TAF had become very concerned towards the end of 1944 about attacks by 'friendly' aircraft in the battle zone, apparently the main perpetrators being fighters of the US Eighth Air Force returning from escort mission. This is when a white circle between the red and blue circles on the upper wing roundels was added later a yellow circle outside the blue circle was also applied.
Sources:
'2nd Tactical Air Force' Volumes Two and Four, by Shores and Thomas.
'Fighter Command Losses of the Second World War' Volume 3, by Norman Franks.
'Fighter Command War Diaries Part 5, July 1944 to May 1945' by John Foreman.
Mike