Can anyone comment on the impact of this result on the theory of Loop Quantum Gravity (LQG)?

My understanding is that one of the predictions of LQG is that photons of higher energy are likely to lag behind those of lower energy due to propagation through spin-foam (meaning velocity isn't c but dependent on energy or frequency).

It seems like this is what they're getting at in [1]...

Would something like this categorically invalidate something like LQG or merely some of its assumptions?

[1] http://phys.org/news/2013-01-spacetime-smoother-brew-knew.ht...