Bloody Sunday reminds me in some respects of the Kent State incident in 1969, when the Ohio National Guard opened fire during a disturbance on the university campus during protests against the U.S. incursion into Cambodia. All it takes is for one guy to open fire on a crowd and then have others join in to produce lots of casualties during a very brief period. The missteps or bad judgement of one side at a civil disturbance does not necessarily imply that virtue is on the other. If I recall correctly Army training for responding to civil disturbances, particularly regarding the loading of weapons, was said to have been revamped after Kent State.