So if play continues as normal after the inadvertent horn we should ignore it and play on. But as soon as the inadvertent horn has an effect on the players in the game, such as when the player in this case picked up his/her dribble, then we should stop play and resume from POI.

Right?

In reality, it usually happens like this. Horn sounds. There is a pause and at least some of the players are obviously distracted. Depending on what is happening at the time, often an official can yell "Play!" and the game continues without incident.