There is no "official acts" to distribute "medical" dope.
A rather perverse determination, since there is obviously an official act that consists of distributing "criminal dope". The objective act is the same, the claim of authority is the same...but somehow if we're selling it to people so we can toss their butts in jail, it all becomes okay.
How odd, then, it is that the federal government acted so quickly and firmly to prevent evidence of Rosenthal's motives from being introduced into court, when motive is the only thing that separates the acts of a professional crack dealer from the identical acts committed by an undercover policeman...
Setting someone up to test the federal law in court is a way to get someone sent to jail.
Or perhaps it wasn't a test case at all. Perhaps the city of Oakland and Rosenthal really and truly believed that the federal government would obey its own laws. Foolish of them, I know...