Rough Play during Jump ball struggle

[Jimgolf]

This may not be what you meant, REFVA, but I'm seeing this as a "no physical contact" type of play, where both players are holding onto the ball and one is knocked to the ground by the other's attempt to wrest it away.

Since there is no physical contact, there isn't a foul, but could the play be deemed unsporting if the knockdown occurs after the whistle has been blown?

The player who got knocked down should have the sense to let go when she is losing her footing, but the opponent should stop pulling the ball once the whistle has blown. IMO, use your judgment.