Hmm the quote doesn’t specifically list a drain.
It does say HAYWARD RECIRCULATION KIT- SKIMMER & 2 JETS
That would imply the filter is fed from a skimmer only and the water returned to the pool via the 2 jets. That saves some plumbing I guess.

The interesting thing I see is the Installation Data that lists the point to point dimensions. I suppose that’s how the problem was discovered.

You can argue it’s their error they are responsible to meet the specs. I guess you have to fight it out with them.

Good luck Mr. Lorentz.