Timer's mistake at end of the game

[doghead]

I am a new (1st year) official. My brother-in-law is a successful high school coach who's boys' team played in the third round of a state play-off game last night. Here's what happened: At the end of an Overtime period, with 4.0 seconds remaining; the score is 58 to 56 (Team A winning). Team B in bounds the ball at end line of their backcourt, dribbles the entire length of the court, gets a two-point shot off and it goes in to tie the game 58 to 58. THE CLOCK STILL SHOWS 4.0 SECONDS! IT WAS NEVER STARTED! My brother-in-law, who is normally composed, goes "nuts". The other coach goes "whacky" too because he wants it to be counted as a three-point shot. Spectators had to be retrained from the scorers' table by uniformed security officers. Those poor officials! I'm sure that one of their comments during their quick conference at center court was, "Now what in the #*&?! do we do?" Let me know what you would have done, then I'll reply and tell you what happened. WOW!