I agree the idea of a compressor stall on an engine in reverse with a heavy fuel leak is frightening. I have been 100 feet in front of an RB211-22C that stalled and it blew me off my feet flat on my back. And yes, there are flames out the front.
But didn't the Concorde report say one of the engines ran up uncontrollably because of ingesting fuel down the inlet? Of course, they were not big fans but straight turbojets.
Anyway, I think they were fortunate not to have any further consequences.