Google Drive – Where Shared Files Go After Deletion

I recently discovered a really weird behavior with Google Drive.
So here is my folder structure:

Folder 1
`-- Folder 1-1
`--- File 1-1-1
`-- Folder 1-2
Folder 2

Folder 1 is shared with a friend User 1 of me and he has access to edit anything containing in this folder. Now he removed File 1-1-1 by accident and I first thought 'Well okay no problem, it will be in my bin or he just removed his access to the file by himself.'.
But non of these cases where actually really true.

I looked in the activity log and saw 'User 1 moved File 1-1-1', I clicked on the file in the activity log and I was still able to access it (It still exists), but I just can't find it in any folder nor the bin. The file also has no Location-label anymore.
We were able to reproduce this x times.

Short: I share a file -> The user who gained access removes the file -> He loses his access -> The file is no longer in the folder in which it was before, nor my or his bin -> The only way to find the file now is from Google Drive search or the activity log.

Also weird: If I share a folder with someone -> He uploads files into the folder -> I remove his access from the folder -> He can't see his uploaded files from the folder anymore, but they still exists and he is only able to find the files via the Google Drive search or activity log.

Edit: I can find the file with advanced search and is:unorganized (https://drive.google.com/drive/search?q=is:unorganized%20owner:me)