That's not what entrapment is. In practice, entrapment is when you goad/harass/coerce someone into committing a crime they wouldn't otherwise commit. Asking nicely for a strangers help to commit a crime does not constitute entrapment.
There are cases which aren't ruled as entrapment which a reasonable person would see that way. Like providing weapons to an edgy teenager posting online and then arresting them for terrorism.
This is not one of those cases. This is open-and-shut buying-drugs-from-the-known-drug-dealer not-entrapment.
Whether what he was doing should be illegal is a more interesting question. Entrapment it is not.
