I would guess that it means they were simply unable to test the entire system.

If you pressurize the line at 1 end and part of the line is blocked, but you have a leak on the far side of the block, then the pressure test will not find that leak. If the ice block is 1 inch away from the pressurization point, then it wasn’t really tested.

That they let the line freeze with water in it could be a little bit of a problem. If there is enough water in the line and it freezes, it can rupture the pipes and you would need to put in new water lines. It isn’t the end of the world but could cost a few hundred to a couple thousand dollars.