That title makes no sense whatsoever. In what way did it "rain marijuana"?
It fell from the sky. Also, people were able to pick it up out of a lake after it fell. Those are pretty rain-like attributes, and not often associated with packaged marijuana. Yes, it happened to be inside a crashing drug-running airplane as it fell, rather than precipitating from a cloud of water vapor, but that's a minor detail.
The closest would be: "a heavy fall // a rain of arrows", but even that implies multiple things coming down over an area, not a single plane crashing.
And all the weed was in close proximity to the plane, not like it was being dumped out as the plane flew overhead and spread out over a large area.
It's semantics, but the headline definitely makes you think that a storm is raining down weed when that's not at all what happened.