Double Dribble or Odd Call?

[Yakivegas]

This has been driving me nuts for the past few days, and I don't think I've found a definitive answer: When initiating a dribble, does the player have to release the ball with one hand?

The question is prompted by a call in one of my daughter's games (5th grade AAU) over the weekend.

Opposing player gets the pass from her teammate, her feet are planted. She starts her dribble, and the whistle blows. I'm expecting a travelling call, but the official signals double dribble. This happened close to the benches in a small gym, so the conversation is easily heard:

Coach: "Did she travel or double dribble?"
Official: "Double dribble, she released the ball with both hands."
Coach (looking perplexed): "Okay"

That was the only call like that the whole game. I wasn't playing close attention to the dribble, maybe she pushed the ball to the floor with both hands like a pass, but even so, would that be a double dribble?