Can developers do something with this? Fix the bug or ban the account pls. I see this is an unregistered account maybe you can ban his ip or something. I've seen several accounts named tty000 or tty007 or the similar ones can do this hack. It really makes you feel bad that someone can shoot you under the water while you can do nothing.
I guess why it was like that. I had put the TriggerDamages in these places long time ago and forgot about it (https://vvcap.com/HqvKEHa3I ). Sometimes upper TriggerDamage for some reason didn't work and player could walk here without any problem (probably fixed in version 3).