Stalling...

[Domer6386]

This was a situation that was encountered in a HS game this weekend..
Team A had the lead in the beginning of the 2nd quarter by 5 points.. For some unknown reason, the Team A coach went into the 4 corner stall to bring out Team B's defense and play them man to man.. Team B's coach stayed in their zone defense for the rest of the game until 5 minutes left in the 4th quarter.. Team B then engaged Team A for the rest of the game... Team B almost won the game...
Many years ago, when a situation as that came up I remember the officials telling the coach (who's team was behind) to engage and come out of their zone.. I also remember North Carolina using their 4 corner stall offense which later was countered by the shot clock being implemented..
What is the proper ruling on this type of play?? Does the Team that is behind have to engage and come out of their zone??
Thanks..
Domer6386