Steps to reproduce:
- Make a few edits on a page
- Revdel some of them
- Go to Special:AbuseFilter/test, add some filter that would match the edit (e.g. 1==1, check "Show changes that do not match the filter", and hit "Test"
- Observe that no deleted edit matches the filter
- Then click the "examine" link next to one of those deleted edits
- Write something that would match the edit, and observe that it does indeed match
IIRC, we show a "not match" by default when the edit was deleted, and that's fine. However, it doesn't make sense to do so if the user is then capable of examining the edit.
This is probably related to T233324 and mentioned tasks, and should be investigated thoroughly because these code paths are very brittle.