If you look at the picture above your post, uphill is to the left and downhill is too the right.
I believe the post you are referencing suggested that the cracks that are forming above the drain pipes on the slabs-next-to-fail indicate that the pipes run “up hill”. That is up hill in the sense that if you were a mouse entering the drain at the edge, you would proceed up hill as well as across the underside of the slab. The cracking in the yet unlighted slabs angles uphill from the edge.
That, at least, was my interpretation of his meaning of “up hill” which would also be normal procedure for a sub-drain or french drain.
My auto correct turned “un-lifted” to unlighted. I am tired of that feature.