I Didn't Know That There Was Going To Be Any Math ???
 

A held ball occurs when: Opponents have their hands so firmly on the ball that control cannot be obtained without undue roughness.

Two players. Four hands. Two hands from one player, two hands from the other: held ball. One hand each: no held ball? Two hands from one player, one hand from another: held ball?

When each opponent has one hand on the ball "Opponents have their hands" on the ball. Between them, there is plurality.

Imagine both players tucking the ball under a single arm as in a football running back and tugging on it. Is there anyone that suggest this is no a held ball?

In which case there are <B>no</B> hands on it. ;)

But I agree with the idea. In the OP, I would've called a held ball as well, only because the player "gave up" and didn't attempt to get the ball away from the defender. I'm normally a little slow in signaling a held ball because I need to see control by both teams, and enough control where, as the rule states, "control cannot be obtained without undue roughness". Because the OP stated they waited a little, and both players had "equal" control, I would've eventually signaled the held ball as well.