Yeah, I had to do an interview anyways, but the process at that point (for me at least) was more of a formality than a decider. They were basically checking to make sure I wasn't a crazy person and that the reference bonus they were about to pay my friend was worth anything.

This mirrors the experience I've had at several jobs, so I don't think it's terribly rare.

Where it's been different than this has been when getting referred to your everyday startup -- and usually those processes are so braindead I end up in a queue for a programming exchange that won't matter in the end. And I've interviewed at some of the biggest "startups" that regularly make front-page here -- so I'm not talking about weird edge cases.