[pa7x1]

This is not true, but I can see how one can lead to think this is the case given the poor journalistic reporting on the subject.

At the time being we have no experimental access to the regime where quantum gravitational effects are relevant. So no theory of quantum gravity has been falsified experimentally. That is, none have failed because they didn't match the experiments. The experiments have not been carried out yet because we don't have the technological ability to do them or we haven't had the ingenuity to infer how to retrieve experimental data from available sourced.