The identified insight is something one could learn from reading the paper, regardless of whether it is a primary result of the paper.
The identified evidence is present in the paper. It is okay if the evidence is weak if that’s the best available evidence in the paper. (For example, if the insight the student identifies is primarily supported by the authors’ professional experience rather than an actual study.)
The weakness identified could substantially affect the technical results of the paper or a reader’s ability to believe/understand those results.