This actually ends up being a condemnation of the English flag, since that flag is a simple white ensign with a red cross on it (the United Kingdom's flag is a combination of England's cross of St. George, then St. Andrew's cross twice, once for Scotland, and once for Ireland).
From the CNN article:
Chris Doyle, director of the Council for the Advancement of Arab-British Understanding, said Tuesday the red cross was an insensitive reminder of the Crusades.
"A lot of Muslims and Arabs view the Crusades as a bloody episode in our history," he told CNN. "They see those campaigns as Christendom launching a brutal holy war against Islam.
"Muslim or Arab prisoners could take umbrage if staff wore a red cross badge. It's also got associations with the far-right. Prison officers should be seen to be neutral."
And what's with "expert" Chris Doyle, quoted above? "It's also got associations with the far-right. Prison officers should be seen to be neutral." Only a total white-bread boy would say something like that. So I googled him. Check out this bio page at his organization's website (total staff, five persons; frequently sought out by the BBC; writes lots of letters to newspapers), that's one white-bread dude.
And as for Saint George, the Red Cross Knight, he killed the dragon centuries ago. It's now time for him to slay the Red Crescent Knight.