Their faces range from no expression whatsoever to a slight smile. But please, don't let that stop anyone from assuming their thoughts based upon a momentary countenance.
As far as offended, no?
One thing I learned from photography, is that you can basically use it to tell any story that you want. Take for example a war. You want to make side A out to be courageous heroes - there are photos you can take to do that. Want to make them out to be homicidal psychos, you can do that as well. A lot of photography depends on the story the photographer is trying to tell.
Compare the war photographs from WWII vs Vietnam. The WWII war photographs in the American press were by photographers who were deeply favorable to the American cause, and so many of the photographs paint the Americans as heroic warriors - the best example being the raising of the flag on Iwo Jima. The Vietnam photos were taken by photographers who were largely opposed to American involvement, and a lot of the most famous photos emphasize either American or South Vietnamese attrocities (the impromptu execution of a captured Vietcong member, the naked, burned child, Mai Lai massacre).
Just looking at the photos and the list of his famous photos, it seems that Don McCullin's sympathies lay with those who were opposed to the capitalist West.
Perhaps look harder.