From my experience with sub-surface drip, it is useless on clay soil where the turf is used frequently be it sport or foot traffic/kids playing. Short term it was very good, but after 4-5 years I found it to be ineffective once the soil was compacted. Lawns just had green circles above where the emitters were, but the water would not spread, regardless of run times.
This sounds like two things to me, a soil management issue and a design issue. If unmanaged compaction was on the table, the design should have been adjusted to compensate. Proper design and installation is critical for SDI, particularly on turf.