At 16:10 of the second period in the Sabres/Senators game, Buffalo requested a Coach's Challenge to review whether an Ottawa player interfered with Buffalo goaltender Anders Nilsson prior to Dion Phaneuf's goal.
After reviewing all available replays and consulting with NHL Hockey Operations staff, the Referee determined that Ottawa's Chris Neil interfered with Nilsson before the puck crossed the goal line. According to Rule 78.7, "The standard for overturning the call in the event of a 'GOAL' call on the ice is that the Referee, after reviewing any and all available replays and consulting with the Toronto Video Room, determines that the goal should have been disallowed due to 'Interference on the Goalkeeper,' as described in Rules 69.1, 69.3 and 69.4."
Therefore the original call is overturned - no goal Ottawa Senators.
Since the Coach's Challenge resulted in the original call being overturned, the Buffalo Sabres retain their time-out.