Leaving floor and starting dribble

[Shooter14]

NFHS

I've always been under the impression that when a player who is in possession feet leave the floor, the player MUST pass or shoot.

But the rulebook says something like (don't have it on me right now) "After establishing a pivot foot-a player who leaves the floor must pass or shoot".

A group of officials kicked around the scenario of a player who catches the ball, doesn't pivot and goes up for a shot can then still start a dribble because the pivot hasn't been established. I still believe this is a travel. How could I convince them otherwise? Or is it not a travel? The rulebook's wording is not very clear on this exact situation because all I can find is "after a pivot has been established" I can find nothing in the casebook.


Thanks!