For example when trying to rollback the 3 edits listed here https://en.wikipedia.org/w/index.php?title=Rachel_Riley&diff=642596311&oldid=642037500 which would actually not change the content of the article.

The message displayed is

Rollback failed
Cannot roll back edit to Rachel Riley by 195.195.24.21 (talk · block · contribs) because someone else has edited the page.
The last revision was by 195.195.24.21 (talk · contribs).

This should instead say something like "Cannot roll back edit to X by Y because the action would result in no page change"