Foundation Drainage Tile

I am adding an addition to my home and had the general contractor put in slotted, corregated PVC drain pipe around the new foundation. This will also pick up a drain that is at the landing of the basement steps (outside the basement door) and empty into a catch basin. I noticed that the contractor did not pitch the pipe. I asked him about this and he indicated that the pipe did not need to be pitched because the hydostatic pressure would force the water through the pipe to the catch basin. This sounds like an excuse for doing a poor job but I am hoping that as long as the point at which the pipe enters the catch basin is the low point of the system it will be OK. Please advise before I get into a confrontation with my general and ask him to trench out around the foundation (which he just filled in).