Another twist is that the Observation Taxon, not the Community Taxon, is what is sent to GBIF, which is another longstanding issue that is very frustrating.
So if someone disagrees to genus and uses the “Can’t be improved” box to send something to RG at the genus level, and then another user comes along and adds a species ID, that species ID will be sent to GBIF, even though it only has one “vote” (and may not be supported).
I’ve also seen observations where there was an initial CV genus ID from the observer and then a single species level ID from an IDer. The IDer ticked “cannot be improved” and the species level ID went to GBIF. Since RG observations get much less scrutiny from IDers, observations like this will get little oversight.