Yet there are those (not me) who argue that a ball that is touched by teammate is automatcially a pass when considering whether a released ball is a pass or dribble in the context of releasing the ball after the pivot is lifted regardless of how the ball was actually released.

Fumble, Pass, Or Whatever ???
 

4.15.4 SITUATION E: While A1 is dribbling in A’s backcourt, the ball legally
touches B1’s leg, causing it to bounce away from A1. A1 quickly recovers the ball
with two hands and then starts another dribble. RULING: Legal. The touch by B1
ended the original dribble and A1 could then recover and dribble again. However,
the touch by B1 did not end team control and the 10-second backcourt count
continues. (9-5-2)

So if the ball hits A2 (instead of B1), then A1 can't legally start another dribble? It may be true, but I'm not sure that I'm calling it that way.

It's definitely not a fumble:

A fumble is the accidental loss of player control when the ball unintentionally
drops or slips from a player’s grasp.

Could it be a pass?

A pass is movement of the ball caused by a player who throws, bats or rolls the
ball to another player.

That's it. It's a pass. Legal dribble. Play on.

I'm with you, Billy. I see no logical distinction between A2 and B1 here, within the rules, to say one is a violation and the other is not.

Oddly, to me anyway, if A1 were to have ended his dribble and then fumbled into A2's leg, he'd be able to dribble again under the more restrictive interpretation offered here.