When a Print Operator installs a 3rd party printer driver on a domain controller, they receive:

Printer driver was not installed - access denied.

Members of the Print Operators group do NOT have Write permission on the %SystemRoot%\Inf folder.

Microsoft drivers don't fail because the .inf files already exist in the %SystemRoot%\Inf folder.

Either install the 3rd party drivers when logged on with Administrator or Server Operators permissions or grant Write permission on the %SystemRoot%\Inf folder to the Print Operators group.