Yeah, I'm blaming the random number generator on this travesty
Assuming fair dice:
Probability of any one die face not showing up in 26 throws: ~5.24% (of a specific face, a sixth of that, so ~0.87%)
Probability of any two die faces not showing up in 16 throws: ~2.28% (of a specific pair of faces, a fifteenth of that, so ~0.15%)
...I mean, I'd LOVE it if 1 or 6 never showed up XD