At 12:56 of the second period in the Capitals/Golden Knights game, Washington requested a Coach's Challenge to review whether Vegas' David Perron interfered with Washington goaltender Braden Holtby prior to his goal.
After reviewing all available replays and consulting with the Referee, the Situation Room confirmed that the actions of Washington's Christian Djoos caused Perron to contact Holtby 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 goal should be allowed because "the attacking Player was pushed, shoved or fouled by a defending Player causing the attacking Player to come into contact with the goalkeeper."
Therefore, the original call stands - good goal Vegas Golden Knights.
Since the Coach's Challenge did not result in the original call being overturned, the Washington Capitals forfeit their time-out.