There have been instances in which I have disagreed with an identification made by someone whom I consider to have knowledge superior to my own. In some of those cases I even think that they are probably right because I have so much confidence in their judgement. What do you do if you cannot make the same identification as an expert does by relying solely on your own knowledge?

In some other instances, the observer has added additional information in the form of an explanation that is not evident in the evidence provided. What do you do if the observer's explanation seems perfectly reasonable?

iNaturalist has addressed these issues.

"On iNaturalist, other users are encouraged to add identifications to each other’s observations, based on the evidence provided, in order to confirm or improve the Community Identification (see further discussion below on Research Grade status)."

"An identification confirms that you can confidently identify it yourself compared to any possible lookalikes. Please do not simply “Agree” with an ID that someone else has made without confirming that you understand how to identify that taxon. If you agree with the ID without actually knowing the taxon, it may reach Research Grade erroneously. "

iNaturalist is saying is that you should only make an identification at the level at which you can confidently identify it by relying solely on your own knowledge. If an expert opinion weakens confidence in your own opinion, then perhaps you should consider not making the identification. But, you should not agree with the expert simply because they are an expert. That would be a duplication of the expert opinion and would constitute two identifications by the same individual.

The same thing holds for cases in which the observer offers additional information in the form of an explanation. The explanation is not part of the evidence presented so it should be excluded in one's determination of the identification - even if it makes perfect sense. Otherwise, iNaturalist could devolve into something that is no longer useful to science.