Maori science is evidently more advanced than western science.
The hind legs were for grappling during mating.
The statement doesn’t refer to the hind legs per se, but to the vestiges of the hind legs; they retained them (a pelvic structure) for mating purposes.
You had to click on the link:
https://www.iflscience.com/why-do-dolphins-and-whales-still-have-pelvic-bones-please-ladies-25634
,,, there's no failed students from Maori universties or other Maori educational institutions. Also, radical Maori Members of Parliament state that Maoris have superior genetics. The colours on the Maori flag are red, white and black - the same as on Hitler's flag.