Player does not sit a tick...or does he?

[bucky]

A scoreboard clock displays tenths of a second only when the time is under 1 minute. With 4:23 on the clock, A2 subs into the game for A1. A2, an inbounder, is heavily guarded by B1. A2 throws the ball but it is immediately batted backwards by B1, hitting A2, who is still out of bounds. When the ball hit B1, the administering official chopped his arm for the clock to start and the timer started the clock. When the ball hit A2, the same official raised his hand to stop the clock and the timer stopped the clock. All of this action happened very fast and the clock still read 4:23. A1 reports to the table and wants to enter the game. The official sees that no time ran and disallows the sub. The timer's display, which always includes tenths of a second, does indeed indicate that some time ran. The timer provides the official with the information.

Allow the sub based on the timer's clock/info?

Allow the sub based on logic of some time must have transpired even though game clock did not change?

Disallow sub based on scoreboard clock not changing?

Other?

Any rule/case out there regarding this?