There's a possibility that the death(s) remain there from the previous player on that slot. nvault_get_array() only fills the array if the player has data stored. So the below sequence of events would cause a connecting player to have data from the previous player.
1. Player A on slot 1 had 4 deaths. They disconnect.
2. Player B connects on slot 1. They have no data stored in the vault so nvault_get_array() essentially does nothing.
3. Player B has Player A's data leftover in pdData array.