Yea that alone (20% vs ~7% increase) with very similar designs on paper is enough to raise some eyebrows, at least. I think even something like the training environment can be huge, train at a hardcore gym and what was once failure is now a 5RIR or more. Perhaps even the demeanor of the exercise scientists can have an impact.

I don’t typically apply untrained studies to my own training but sometimes keep an eye on them as not all clients are fully “trained”…at least before I get through with them! :)