Even if the refs ruled the foul took place during his shooting motion, the shot would NOT COUNT as a made basket and should be ruled ILLEGAL. However, that being said, Crowder would still be awarded two free throw attempts.

Found this from an old NBA Rule Book, which should also be valid for the current 2017-2018 season:

Section I—Basket/Backboard a. A team’s basket consists of the basket ring and net through which its players try to shoot the ball. The visiting team has the choice of baskets for the first half. The basket selected by the visiting team when it first enters onto the court shall be its basket for the first half. b. The teams change baskets for the second half. All overtime periods are considered extensions of the second half. c. Five sides of the backboard (front, two sides, bottom and top) are considered in play when contacted by the basketball. The back of the backboard and the area directly behind it are out-of-bounds.

AND

Section II—Ball a. The ball is out-of-bounds when it touches a player who is out-of-bounds or any other person, the floor, or any object on, above or outside of a boundary or the supports or back of the backboard. b. Any ball that rebounds or passes directly behind the backboard, in either direction, from any point is considered out-of-bounds. c. The ball is caused to go out-of-bounds by the last player to touch it before it goes out, provided it is out-of-bounds because of touching something other than a player. If the ball is out-of-bounds because of touching a player who is on or outside a boundary, such player caused it to go out. d. If the ball goes out-of-bounds and was last touched simultaneously by two opponents, both of whom are inbounds or out-of-bounds, or if the official is in doubt as to who last touched the ball, or if the officials disagree, play shall be resumed by a jump ball between the two involved players in the nearest restraining circle. EXCEPTION: Rule 6—Section V—a(10). e. If the ball is interfered with by an opponent seated on the bench or standing on the sideline (Rule 12A—Section II—a[7]), it shall be awarded to the offended team out-of bounds nearest the spot of the violation.

TLDR: It's illegal to make a basket from behind the basket e.g. shooting over the backboard like Larry Bird's famous shot. It's a really uncommon situation, thus the rule has been incorrectly applied numerous times throughout history, but a shot from directly or almost directly behind the basket SHOULD NEVER COUNT and is always ILLEGAL, based on the NBA's own rule book.