https://www.nature.com/articles/s41586-019-1256-6
Authors. Berlinguette et al
Venue. Nature 570
How the Institute flags it
established 3 times frontier 1 time
This source carries more than one flag across the corpus. That is not an inconsistency to resolve: the same work can be established evidence for one claim and frontier evidence for another, and the flag belongs to the use rather than to the source.