Incorrectly removed tree matches

Yes, there is.

1) there is supposed to be a way to see rejected matches for a profile even if no current ones - Maybe someone else knows how

2) If you can access each profile in the pair, you can merge even if Geni is not suggesting -- this gives links to several ways: https://help.geni.com/hc/en-us/articles/229705547-How-do-I-merge-du... -- my current favorite is "Merge This Profile"

I tried but it said 'merge already declined' or something like that. Surely since it's all meant to be collaborative there should be a way to look over removed ones just incase there was a mistake

Private User - post in https://www.geni.com/discussions/272643
If both Profiles are ones you can edit, you should be able to merge them using "Merge This Profile" - quite sure I did so in the past one time. But Geni keeps changing.

They did a lot of work so merges can be undone. Many time the request has mentioned accidentally hit wrong key. Of course one can also hit the wrong key and reject a merge.
Give links to both profiles in your post - copy and paste address line to do that.