As far as I've been able to tell, Apple engineers use "file a radar" to mean "I'd rather let someone else triage that, or even better yet I'd rather you get lost in the system, so here's a quest for you to go on so I can get back to work", particularly as we all know that at the end of that quest the result will be "marked as duplicate", past which point Apple refuses to give you any more information or even a follow-up. I would honestly rather there just be an e-mail address bugs@apple.com to which I could shoot off random issues I run into, from which I know I'd get no response, than Radar.