new construction unlevel floor questionable repair
 

I recently had a contractor add a 2 story addition to my house. After
finishing the ceiling below and the hardwood floor above, I noticed that
it was not level. There was about an inch and a half variation across
about 12 feet from one side to the other. The floor above this ceiling,
meaning the 2nd floor was also unlevel especially at the corner where the
2 walls meet. This is new construction over a concrete slab foundation.
After I noticed, the contractor removed the sheet rock from below and used
a car jack to raise the plywood subfloor where it was low. He also did
some sawzall cutting and hammered t down the floor where it was high. He
then used adhesive to glue the plywood subfloor to the shims and bridge
the gap to the existing beam. He assured me that this is ok but I am
skeptical. I paid quite a good deal of money for a quality job and do not
want any structural damage months or years from now. Is jacking and
shimming a standard acceptable method for new construction? Can beams be
sawzalled and adjusted after framing and finishing is complete? Please
help.