from the Real World
There have been many screen adaptations of Robin Hood, but it is difficult to determine which one it was. It may have not been any Robin Hood film that existed in the real world. The Park Row tragedy that happened shortly after their viewing of the film would have had to have happened sometime between 1950-1952, this is assuming Bruce was eight years old, ten at the most. In most versions he's said to be around that age.
In the real world, there were a number of Robin Hood films that came out between those years. Among them were Rogues of Sherwood Forest (1950), Tales of Robin Hood (1952), Disney's The Story of Robin Hood and His Merrie Men (1952) and Ivanhoe (1952). Since the title was simply RoBIN HooD, and since we don't know the exact year the Park Row tragedy occurred, it's impossible to know for sure which movie, if any of them, it was supposed to be.