I think the tragedy in Aurora indeed affected the box office. I live all the way here in Ecuador, South America and my girlfriend was afraid that something bad could happen in the midnight opening in our town, I know its dumb but people got scared specially in NA.
Anyway I never thought it would made more money than Avengers I just wanted a great film and that it could be financially succesful enough to keep Nolan making films without sacrificing his artistic integrity (thanks god he didn't made TDKR in annoying 3D) and thats what I got.