The other answers do a great job explaining why economic freedom might not be well correlated with unemployment, mine looks at the specifics of the situation in Hawaii.
Living in Hawaii is absurdly expensive. The cost of living in Honolulu is 88% higher than the national average. This article describes the problem in more detail, "According to the U.S. Census Bureau, 47 percent of Hawaii's residents spend more than a third of their monthly income on rent. That's greater than any other state. About one-quarter of renters put half of their income toward housing."
Furthermore, low paying hotel and restaurant jobs "accounted for 60 percent of Hawaii's job growth in 2017, according to data compiled by Moody's Analytics. Hotels and restaurants employ about one of every five workers in the state, double the proportion in the rest of the U.S." So there are lots of jobs available, but the money they bring in relative to the cost of living makes them unattractive. In a large part due to this phenomenon, "People are moving away from Hawaii even as employers here clamor for workers... [in 2017] the state suffered a net loss of more than 1,000 people. On Oahu, home to Honolulu and major military installations like Pearl Harbor, the population declined an average of 11 people per day."
So the cost of living makes Hawaii unattractive for the kinds of jobs available, making people leave the island. This leaves lots of openings for unemployed people on the island to take, making the unemployment rate very low.
How does this relate to economic freedom? From the original article on economic freedom "Hawaii does badly in almost every area of regulatory policy, but its two worst categories are land-use and labor-market freedom. It has among the strictest restrictions on residential building in the country." Restricting building keeps new residences from being built to lower the cost of living. The source from the question also describes cronyism and a 'general “unfair sales” law (you are not allowed to sell at prices that are “too low”).' Keeping competition from lowering prices could push up cost of living as well. Pushing cost of living up makes people leave and thus drives unemployment down.
Of course, there are other explanations for the cost of living being high, like tiny islands having limited land and the cost of shipping everything from the mainland which are unrelated to government action.