Please see: https://www.youtube.com/watch?v=WxY47I-pc-Q
Greg Anthony (the commentator) is quite insistent that this should have been a jump ball. But it looks to me that the ball was not in Hibbert's "continuous possession" (as required by the rules, see below).
Instead, it looks like Hibbert went up, Millsap blocked it, ball completely left Hibbert's hands, Hibbert rebounded the blocked shot (albeit while still in the air), and came back down with it (just like you would when getting any rebound). So this shouldn't be a jump ball (and the officials got it right with their no-call). Is my interpretation of the rules correct?
A held ball occurs when two opponents have one or both hands firmly on the ball or anytime a defensive player touches the ball causing the offensive player to return to the floor with the ball in his continuous possession. (p. 19 of this PDF)