How important is the orthographic/typographic rigor?
Orthography and typographical correctness are much less important than scientific (methodological and theoretical) rigour. Yet all scientific publications should of course also be well-written, and in general there's nothing wrong with casually pointing out a typo, wrong glyph, or similar glitch.

However, if you're writing a review, grade a student paper or discuss a presentation, this better not be your only comment!