At 19:50 of the first period in the Bruins/Blues game, St. Louis requested a Coach's Challenge to review whether Boston's Joakim Nordstrom was off-side prior to Sean Kuraly's goal.
After reviewing all available replays and consulting with the Linesmen, the Situation Room confirmed that St. Louis defenseman Joel Edmundson passed the puck back into his own defending zone prior to the goal. The decision was made in accordance with Rule 83.1 which states, in part, "If a player legally carries or passes the puck back into his own defending zone while a player of the opposing team is in such defending zone, the off-side shall be ignored and play permitted to continue."
Therefore, the original call stands - good goal Boston Bruins.
Since the Coach's Challenge did not result in the original call being overturned, the St. Louis Blues are assessed a minor penalty for delaying the game.