At 15:59 of the second period in the Capitals/Stars game, Dallas requested a Coach's Challenge to review the "Interference on the Goalkeeper" decision that resulted in a "no goal" call.
After reviewing all available replays and consulting with NHL Hockey Operations staff, the Referee determined that Dallas' Jamie Benn did not interfere with Washington goaltender Philipp Grubauer before the puck crossed the goal line. The decision was made in accordance with Note 2 of Rule 78.7 (ii) which states, in part, that "the attacking Player's positioning within the crease did not impair the goalkeeper's ability to defend his goal and, in fact, had no discernible impact on the play."
Therefore the original call is overturned - good goal Dallas Stars.
Since the Coach's Challenge resulted in the original call being overturned, the Stars retain their time-out.