Sure. From those choices, the only one that makes sense is that he didn't perform enough trials. Technically, you can't expect the experimental probability to match the theoretical probability until you've rolled it an infinite number of times.
I have a hunch that even for only 60 trials, such a great discrepancy between theory and experiment is beginning to suggest that the cubie is loaded. But you really can't say. You just have to keep trying and watch how the numbers add up.
