Whether there's damage depends on 1) the g-force when the phone stops and 2) the angle of that force. If you drop a phone just right (wrong?) 6" onto soft wood you can crack the motherboard (which is fiberglass, which is pretty strong) while dropping it 5 feet to concrete may not do any more damage than scratching the case. In your case, the force plane must have been through the screen or across it just at the angle needed to break something.
They're making water-resistant phones now, but no one has made a really shock-proof phone since Nextel made a couple. And you could break the flip phone by throwing it against a wall at just the right angle when it was open. The candy bar model just wouldn't break (I never tried driving over it with a tracked vehicle, though). We used to throw it to the floor really hard to demonstrate just how shock-proof it was. The store phone must have been thrown hundreds of times, and it didn't have a problem until Nextel went out of service (except that the battery door would pop off and the battery would come out). And, IIRC, it was waterproof, to a few feet at least.