At 1:46 of the third period in the Blues/Senators game, Ottawa requested a Coach's Challenge to review whether St. Louis was off-side prior to Patrik Berglund's goal.
Review was not conclusive in determining whether St. Louis was off-side prior to the goal. According to Rule 78.7, "If a review is not conclusive and/or there is any doubt whatsoever as to whether the call on the ice was correct, the On-Ice Official(s) will be instructed to confirm their original call."
Therefore the original call stands - good goal St. Louis Blues.
Since the Coach's Challenge did not result in the original call being overturned, the Ottawa Senators forfeit their time-out.