We are getting our basement finished by a contractor. He had to break the basement floor to move the shower drain as it was roughed in too close to the wall, and shower stall wouldn't have fit there. He had to hammer jack a "hole", which was about 1-1.5ft in diameter, and about foot deep. After extending the shower drain so it was farther from the wall, he just put the shower stall base on top of it without filling the hole with cement/concrete first. He said it wasn't needed. Does it matter? Should I be worried? They have just put up drywall on the frames so if I insist that they fill the hole in the floor, they would have to take down the drywalls to do that. So, I want to make sure that the hassle was worth it. Could you please provide some guidance? Thanks much