i had path of knives on my character. I jumped from one Victory Point diagonaly to the other and lost only 4HP. It means it calculated only the distance start-end of move not the only possible route to reach the end. Anyway that sounds wrong
I don't suppose you had any other cards either attached or in hand that may have affected this? I assume you would have noticed damage reduction due to Armor, but anything with Teleport would allow you to do this by moving only two squares rather than the four squares that would normally be required.