Break inheritance item level access denied on upload by another user

Question

I have a document library custom view that shows only the documents that the user has access to. Already implemented solution: View that breaks inheritance on item level and assigns only the author as the one who has access to this item.

• Issue: Users uploading documents that already exist in the library will receive give "Access denied" because document already exists but the current user uploading doesn't have access to it.
• Todo: Display a friendly user message instead of "access denied"
• What I tried: Event handler on itemadding/added/updating. These are not triggered and access denied is displayed no matter what.

Obs: Existing technical solution with inheritance break on item cannot be changed.

Any ideas ?