2 points to be aware of:
1. The journal this is published in is not held in high esteem by most paleontologists. This may be telling; I imagine the paper was rejected by several other journals before ending up here. Peer review seems a little light at PE. That doesn't mean it's wrong, but calls for caution.
2. Everything hangs on the authors' interpretation of the age of the sediments; the bones don't seem reworked (i.e. moved around from older sediments), which is one source of error, but he could be wrong with the radiometric age estimation, which even in the best cases has a moderate margin of error.
BUT it remains an interesting question of any dinosaurs survived long past the extinction; most of our picture of the K-T event comes from central/western North America, so who knows what happened elsewhere.