Question rugby pro loose back cover

I dont see any seal or gasket on the back cover or in the phone should there be one to keep the water out or did mine get left out?

The screw that holds the back cover on seems loose it will turn to unlock in my pocket .if I blow on it hard enough it may turn to unlock.Are all rugby this loose?

I can push down on the back cover near the bottom side and the top side will pop out.Do you think the back cover is defective or are these just that loose ?

It will definitely not keep water out.