thanks for the comments KC - looks like you really know this stuff. Where do you goto school?
i'm confused by your statement in number 4 that you think the party was "joined under rule 13". i thought rule 13 was only a reference to bringing claims (counter and cross), not a reference to adding parties. doesn't 13 only apply once a party has been added, and as such would not negate 1367(b)'s statement that since the party is joined under rule 20, and the plaintiff is bringing the claim against him, supplemental jurisdiction would not be allowed?