A forbidden point is rarely guilty of only one thing. The centre point here breaks the rules twice over: taking it would complete a four down the column AND a four across the row (a gap four and a straight four sharing one stone — that is a double-four). A step to the side breaks a different rule: two threes through one point — a double-three. White wins either way: black plays a forbidden point and the game ends. Learn to see the stacking — every line through the point counts separately. And remember the asymmetry: each of these points is a legitimate fork for white and a funeral for black, because the rules bind one player only.
Finish this step to move on.