After reviewing all available replays and consulting with the Referee, the Situation Room confirmed that Alex Ovechkin interfered with Petr Mrazek by pushing his pad, which caused the puck to enter the net. According to Rule 69.3, "If an attacking player initiates contact with a goalkeeper, incidental or otherwise, while the goalkeeper is in his goal crease, and a goal is scored, the goal will be disallowed."
Therefore, the original call is upheld - no goal Washington Capitals.
Since the Coach's Challenge did not result in the original call being overturned, the Washington Capitals forfeit their time-out.