Didn't check it with a tool, I guessed based on the comment. But right there - that's what causes it to know Hydro Pump at level 1. If you follow the bulbapedia order (the one used in gen VI), the level 1 moves later in the list overwrite Fell Stinger, Hydro Pump, and Destiny Bond. You just have to change the order and Qwilfish will (correctly) have Water Gun, Spikes, Tackle, and Poison Sting at level 1. You might have the same problem with other Pokemon having OP moves at level 1 if you weren't copying the order.