Player on court during time out

[WhistlesAndStripes]

Originally Posted by Nevadaref

Rule 2-7-4: The officials shall conduct the game according to the rules. This includes: ... Prohibiting practice during a dead ball, except between halves.

It seems to me that a player technical foul for unsporting behavior is appropriate for violating this rule.

So the rule book puts the responsibility on the officials to prohibit practice during a dead ball, but where does it say the players are forbidden and accountable for this? How do your justify this as "unsporting behavior"?