This is a sharp observation, and it points at something a lot of people miss when they try to diagnose their Verbal timing. Rereading is one of the biggest time drains in the section, and it rarely shows up in per-question-type data because it isn't concentrated anywhere. It's spread across everything.
It's worth separating two things that look identical from the outside, though. One is what you described: comprehension that was actually complete, followed by a second pass driven by doubt rather than need. That's a confidence habit, and committing to the first read fixes it. The other is a first read that genuinely didn't land, where the rereading is the mind compensating for reading that was passive, or too fast, or not organized around anything. If someone in that second situation forces themselves to read once and commit, they don't get faster. They get wrong answers faster.
What makes a single pass sufficient is reading with a structure in mind. On RC, that means knowing the main point, why each paragraph is there, what the author's stance is, and roughly where the key details sit. On CR, it means understanding the argument, the evidence, the conclusion, and what links them, before touching answer choices. When the read is organized that way, there's much less to go back for, because you know what you read and where it lives.
One caveat on the word commit. Going back to the passage to confirm a specific detail for a specific question is part of the method, not a failure of it. The passage stays on the screen for a reason. What you eliminated was rereading out of doubt, which is a different thing, and worth keeping distinct so nobody reads your advice as a rule against ever looking back.
I'd also put the reading discipline and the content work side by side rather than one above the other. Content review is what gives you the skills to process a dense passage or a tricky argument on the first pass. The reading discipline is what makes sure you only need to do it once. Neither one gets you there on its own.
Good insight, and thanks for sharing it!
quasivoluptatem
Same story as DI but in Verbal — I wasn't slow on any one question type, I was slow on rereading. Multiple passes over the same RC passage or CR stimulus because I didn't trust my first read. Forcing myself to read once, actively, and commit did more for my Verbal timing than any content review did.