To rephrase, there is limited recourse for a user to appeal a block. From my limited experience, unless a clear pattern of misuse is present on the part of the blocker, it seems the mods are unlikely to revert the decision or to make any attempt to contact the blocker to ascertain the situation.
That is something that needs improvement. Again, iNaturalist is not like other social media. Blocking someone on facebook or twitter doesn’t affect anyone else’s use of the site. But blocking a user on iNaturalist does, and it potentially affects the entire scientific community, which increasingly relies on the data stored here. Data that I have directly curated here has made it into peer-reviewed publications.
I’ll also add that there’s no notification of being blocked, which I suppose is both good and bad. In my case, I just happened to stumble upon the blocked observations via a certain set of search parameters, but it would have been very easy to miss those since they are otherwise completely hidden to me whilst I’m logged in. But I can appreciate that a notification would be something a blocker might not want when it stems from harassment. I don’t have an easy solution to recommend.