They used 450umol/s/m2 for all lights. So it's really only a morphology test as they clearly explain in the abstract.
The biggest win for leds is in efficiency and that's specifically left out of this research paper. If you look at this from g/W perspective, leds would win by a huge margin again. On all fronts.
Instead, they set out to see if there was any truth to the "Yes LED might be much more efficient, but HPS produces much better product, so there!". Which in fact turned out to be false as the results of these tests show.
The advantage in HPS yield (at 450umol/s/m2) is offset in this test by higher cannabinoids yields for the leds (also at 450umol/s/m2) in this test. Not sure if that always matters, but still.
So, it's not a lie at all. You simply misunderstood what they set out to test.