Chris didn't touch on the subject, but as far as I am concerned, it is not a bug.
If you use the red flag to report a message as Spam, the system automatically reports the member as Spammer on your behalf as well.
If you use the red flag to report a message as Abuse, the member is not reported as Abusive. As far as I can tell, the member is not even deducted any points.
I think it is obvious this behavior was put in place to quickly get rid of members that post actual spam in the forums - I am sure many members will see a spam message and report it as such, but not bother going to the profile to report the offending member directly.
The trick is to get people to red-flag posts like the one in question as Abuse and not as Spam. A few of those and the post is gone without hurting the posting member.
"When you don't know what you're doing it's best to do it quickly" - Jase #DuckDynasty
Anything that is unrelated to elephants is irrelephant Anonymous ----- Do not argue with an idiot. He will drag you down to his level and beat you with experience Greg King ----- I had the right to remain silent, but I didn't have the ability! Ron White, Comedian