Well, there is are a lot of observational evidence for black holes - the by far most likely scenario is that the model they analyzed does not describe the physics of black holes in our universe.
This is the first question I thought of. I'm not a physicist so I dare say I can't interpret the paper but I'm curious how she explains the seemingly observed orbits of stars around the black hole in the middle of our galaxy and others[1][2].
[1]http://astro.uchicago.edu/cosmus/projects/UCLA_GCG/ [2]http://en.wikipedia.org/wiki/Accretion_disc