supply in slab or walls?

At an inspection yesterday, home built on slab, I could not find any place where the plumbing supply was visible. Seller was present, he insisted that the supply was in the walls, not coming through the slab. He did state that the water service from the meter came through the slab, and he agreed that the plumbing drain system was in the slab. Since I could not see any of that, I just had to state in the report that I couldn’t confirm the seller’s statement. Oh, and no plumbing visible in attic, either.

I did notice that the individual supply lines under the bathroom and kitchen sinks came from below (from the direction of the slab) as opposed to coming out from the walls. Based on that, my assumption would be that the supply is coming through the slab. But I did not actually see pipes coming out of slab, since the cabinets had floors in them. I suppose the cabinet floors could conceal a turn, pipes going into walls?

Now I’m wondering if I missed something. What are some clues to look for in finding plumbing supply lines with a slab?

James, I don’t think your missing anything. With a slab the plumbing is under the concrete and stubbed up at the necessary locations. If there are no plumbing vent pipes terminating through the roof the builder missed something though.