It does not appear from the explanation that the crank sprocket slipped while the crank kept turning. I would do a compression test just to make sure. It is strange though that if the crank bolt loosened off enough to cause the pulley pin to break and the pulley to stop turning, that some damage would not have occurred on the sprocket key and cause that to slip as well. If this is the case I think pampaskat is very lucky or prays to the right god. I guess the pin is in fact "puny" and not up to much torque if the bolt is not torqued properly.

92 Montero LS 3.0L V6 Auto, Stock, Original owner, 185,800K miles