If I deop myself and replace both params, as you may have guessed, I get the "You are not an op" error message.
- That's the bug he's pointing out. Since the .
has been specified to make the command silent there shouldn't be any warning messages. It's kind of half-bug half-feature suggestion since it's arguable that it's not really command output but an error message. Still, it does make sense that it shouldn't display in that instance.