How do they know how far the drone flew? Could be just Lawrence of Arabia on a camel crossing the desert and launching from outside the compound wall for all anyone knows.

Could be just that, but it doesn’t seem that’s what happened https://twitter.com/tobiaschneider/status/117291970014739660...

The drone doesn't need 1000km rage, you just need a pickup and a few people to get somewhat close.

The attack was, per their claim, carried out with assistance from inside Saudi Arabia.

The required range is vastly smaller than 1000km.