If you ever need to figure out which files/folders a user is explicitly defined on here's a nice PowerShell one-liner.

This enumerates all files/folders in a directory, checks the ACL for each file/folder and if that ACL contains any NTFS permission for a specified user.

Get-ChildItem 'FOLDERNAME' -Recurse | Where-Object {(Get-Acl $_.FullName).Access | Where-Object {$_.IdentityReference -eq 'DOMAINUSERNAME'} }