Thnik of gravity. Water only goes down. Unless your kitchen waste falls through piping which you can intercept at a point LOWER than the one you are planning for the basement, your friend is correct.

Do you have an ejector pump in your basement? If so, you might be able to run piping around the perimeter to meet up with it. That would save cutting your concrete floor. Ours runs on the peremiter walls. A diagram of our basement is posted at "My Page". Though it does not specifically indicate plumbing, I believe you can get the idea. Only need to drop 1/8" per foot of run, so you can carry the waste a long distance.

Code requires all pipes 3" or less in diameter to be run with a 1/4" per foot pitch.

Under some circumstances a 3" line may be run with a 1/8" per foot pitch with the expressed written consent of the inspecting authority.

Ref: International Residential Code 3005.3 & Uniform Plumbing Code 708.0