Reports but Doesn't Enter

[Rick Durkee]

MJT posted a question about a team member reporting to substitute for a player shooting a free throw and then replacing a different player after a made shot. All seemed to agree that this was permissible.

What if, after the made free throw, the horn sounds for the substitution but the team member does not enter when beckoned and returns to the bench? I don't see any rule that makes it illegal. Is there a rule that would prohibit this "strategy"? If the rules do not specifically prohibit the practice, it seems to me that an official could be justified to rule an unsporting technical for multiple occurrences. What say you all?