As I see it, with the bond in the panel missing, the only earth-fault path would be via pipework and/or a ground rod, if fitted. You would have effectively changed to a TT arrangement, and if there is no RCD fitted, a fault would probably not result in enough current to trip an MCB or blow a fuse.
If all the water supplies feeding the group of houses have metallic paths throughout, then you would still have a fault path via the pipework and the neutral of another house.
