That's an interesting point, Shmuel. If you at all care about the details: In this case, it was a matter of whether or not an action had been approved at a meeting. At the meeting in question (to the extent that we were even using RONR we were using small board rules), I do believe he made a good faith effort to get unanimous consent on an action, but everything was so casual--people were actually collecting their coats--and it was brought up so ambiguously, that at least 5 of the 9 people there had no idea that an action had been proposed (let alone approved). The action was carried out, and most of those who did not think we had approved the action did not want it to appear in the minutes that we had (and since there was no vote, the only thing that could go in the minutes was that it was approved by unanimous consent, which implicated us). To make a long political story short, come the next meeting, it looks like the 2 people who were not at the previous meeting are the swing voters. So the chair, who has a lot of sway over these two voters politically, argues that RONR says those people have a duty to vote on an amendment to the minutes (we all assume they will vote his way), and those of us on the other side argue that they have no basis for forming an opinion on what happened during the meeting since they weren't there, and should abstain (in which case we win).
We have since resolved this (nothing went in the minutes about whether the action was passed), but the chair continues to make this point that those not at a meeting have "a duty" or are "encouraged" to participate in minutes approval in every case. At this point he's probably just trying to save face. But I would definitely love to get second and third opinions on this situation.