At 0:27 of the third period in the Maple Leafs/Golden Knights game, Vegas requested a Coach's Challenge to review whether a Toronto player interfered with Vegas goaltender Malcolm Subban prior to Auston Matthews' goal.

After reviewing all available replays and consulting with NHL Hockey Operations staff, the Referee confirmed no goaltender interference infractions occurred before the puck crossed the goal line.
Therefore the original call stands - good goal Toronto Maple Leafs.
Since the Coach's Challenge did not result in the original call being overturned, the Vegas Golden Knights forfeit their time-out.