Catcher's Balk

[andrewm]

USSSA 12U (OBR with safety modifications), R1.

R1 attempts steal of 2B. F1 pitches-out to F2. F2 begins movement out of the catchers box prior to release of the ball by F1. R1 is thrown out at 2B, but PU calls catcher's balk, awards R1 2B. According to 4.03(a), isn't it only a balk if an intentional walk?

4.03
When the ball is put in play at the start of, or during a game, all fielders other than the catcher shall be on fair territory.
(a) The catcher shall station himself directly back of the plate. He may leave his position at any time to catch a pitch or make a play except that when the batter is being given an intentional base on balls, the catcher must stand with both feet within the lines of the catcher’s box until the ball leaves the pitcher’s hand.
PENALTY: Balk.

1. Was a balk the wrong call?
2. If so, is this protestable?

Thx