NHTSA to Tesla: Stop claiming your cars the safest.
tl;dr:
Telsa has been lying about the results NHTSA produced.
From your link (my emphasis):
The agency has a five-star safety rating system, awarding more stars to cars that perform better in its battery of safety tests. The Model 3 earned five stars across the board, for having low risk of injuries to left- and right-seat front passengers in front crash tests, and left-side front and rear passengers in two left-side crash tests simulating being hit by another car and hitting a pole on the side of the road. The Model 3 also received five stars in NHTSA's dynamic rollover-propensity test. Last month, NHTSA finished testing the all-wheel-drive Model 3 Long Range Dual-Motor, which earned the same five stars across the board, earning the entire Model 3 lineup the same across-the-board five-star rating.