Hitting the Ball with One's Fist

[chymechowder]

This happened in a men's league game I was officiating:

A1 is bringing the ball up, dribbling in his backcourt. He's not covered, but he loses the handle on the ball. It's rolling slowly in front of him when he strikes it with the heel of his closed hand to get it to bounce back up so that he can continue dribbling it.

I'd never seen that before. My first thought was: Wait is that a violation for striking the ball with a fist? But Men's league + Team B not playing defense = no whistle.

But would you call this in a Varsity high school game? Would it matter whether Team B had caused the interrupted dribble or not?

Also got me wondering: what's the intended reasoning behind the rule? Is it a control issue? Or a safety issue?