Rapaire, that's a hell of a read.

This bit I have seen confirmed by British social histories of the war:

Racial friction also developed in Great Britain where some American troops, resenting their black countrymen's social acceptance by the British, tried to export Jim Crow by forcing the segregation of recreational facilities. Appreciating the treatment they were receiving from the British, the black soldiers fought back, and the clashes grew at times to riot proportions. General Davis considered discrimination and prejudice the cause of trouble, but he placed the immediate blame on local commanders. Many commanders, convinced that they had little jurisdiction over racial disputes in the civilian community or simply refusing to accept responsibility, delegated the task of keeping order to their noncommissioned officers and military police. These men, rarely experienced in handling racial disturbances and often prejudiced against black soldiers, usually managed to exacerbate the situation.

As you might imagine, the thing that really ticked off the white racists in the military was when British girls took up with black GIs.

Some social historians come close to blaming the degeneration in race relations in post-WW2 Britain entirely on the US military's behaviour when over here. That goes way too far, but they sure didn't set a shining example.