While reading primary science literature, I've had the following experiences happen to me on multiple occasions.

1) Read a paper with a surprising result. Later discover it has critical flaws or didn't pass replication. I've learned to increase skepticism with increasingly surprising results. "This study is just wrong because of statistical issues or bad reporting" is now always one of the hypotheses in my mental arsenal, and I've found myself getting a bit better at predicting which results are just wrong using largely the heuristic of "this is too surprising to believe"

2) Form a hypothesis while reading. It gets verified (or falsified) via something you read later. Also, since one typically reads the methods before the results, one gets a lot of practice predicting results. (I don't formally make predictions but I find myself making them automatically as I read.)

Based on these experiences, I suggest that reading primary scientific literature is a good exercise in "alive" epistemic rationality training. The only drawback is that it takes a long time to get sufficiently acquainted with a field.