There’s nothing on GBIF either (which would lag iNat by a couple weeks potentially if someone deleted their account).
I agree with @pisum - It seems more likely that there weren’t observations there to begin with.
But based on the evidence reported here it isn’t possible to rule out a scenario with one user with all the observations and ids of that species deleting their account (and thus observations) in a fairly small window of time (I think…)
I have noticed that all the observations are completely gone from inaturalist, it must have happened not too long ago. I have visited the plant’s page before and the plant had many observations from many users over years.
it’s possible that none of those observations were included in the AWS data sets (being all observed by one or a few people who did not license their observations), but if there were “many observations over many years”, it’s more likely that the claim is just wrong.
at this point, i think the burden is on the Redditolr to show some evidence for their claim.
I notice there are only 40 “wild” observations of Lilium speciosum, only 58 if I remove the “wild” filter. That alone limits us to two scenarios: there were a bunch of Lilium speciosum, but more recently they were IDed as something else (I think @pisum has ruled this out); there never were very many observations of Lilium speciosum, and quite likely none in Japan at any point in iNaturalist’s history.