Not a rules expert but I don’t t think the arc rule applies on elbow throws, only charges taken when the offensive guy is jumping/landing. Given that basketball is highly leveraged to momentum swings, it was a critical and game changing call.
Agree with rest of your post. Also not sure my interpretation of arc rule is correct and too lazy to research.
Here are the rules for the restricted arc copied straight out the NCAA Men's Basketball Rule Book that I happen to have handy:
Art. 14. A secondary defender as defined in Rule 4-36 cannot establish initial legal
guarding position in the restricted area for the purpose of drawing an offensive foul
when defending a player who is in control of the ball (i.e., dribbling or shooting)
or who has released the ball for a pass or try. When illegal contact occurs within
this restricted area, such contact shall be called a blocking foul, unless the contact
is a flagrant foul.
a. When illegal contact occurs by the offensive player leading with a foot or
unnatural, extended knee, or warding off with the arm, such contact shall be
called a player-control foul
.
b. When a player in control of the ball stops continuous movement toward
the basket and then initiates illegal contact with a secondary defender in the
restricted area, this is a player control foul.
c. This restriction shall not apply to a secondary defender who establishes legal
guardian position in the Restricted Area Arc and jumps straight up with
arms in legal verticality position and attempts to block a shot.
Art. 15. Illegal contact caused by the swinging of the elbow(s) that:
a. Results from total body movement is a common or flagrant 1 personal foul;
b. Is excessive per Rule 4-18.7 is a flagrant 2 foul, or
c. Occurs above or below the shoulders of an opponent is a common, flagrant
1 or flagrant 2 personal foul.
Art. 16. Illegal (not incidental) contact with an elbow that does not involve the
swinging of the elbow shall be considered a foul.
Rule 4-18.7 flagrant 2 foul
Flagrant 2 personal foul. A flagrant 2 personal foul is a personal foul
that involves contact with an opponent that is not only excessive, but also
severe or extreme while the ball is live. In determining whether a foul has
risen to the level of a flagrant 2, officials should consider the following:
1. The severity of the contact;
2. Whether a player is making a legitimate effort to block a shot. Note
that a player may still be assessed a flagrant 2 foul on an attempted
blocked shot when there are other factors such as hard contact to the
head or the defender winding up or emphatically following through
with the contact);
3. The potential for injury resulting from the contact (e.g., a blow to
the head or a foul committed while the player was in a vulnerable
position), and
4 Any contact by the offending player to the groin area of an opponent
which is not clearly accidental.
5. Any foul similar to the foul described in Rule 4-15.2.c.7 in which
the contact, or the result of the contact, is not only excessive but also
severe or extreme.