Water itself may not be, but during a cataclysmic flood, it can create that type of environment. To wit, 1500 Guatemalans were buried in a mudslide caused by a few days of torrential rains. So I guess we both could be correct (landslide caused by lots of water).
The point is this: it is all conjecture and either conclusion is an act of faith because we weren't there to witness the event.
All we can do is draw conclusions based on the available evidence. And the fact is, there is no available evidence of a global flood.