At 9:02 of the third period in the Oilers/Bruins game, Boston requested a Coach's Challenge to review whether Edmonton was off-side prior to Patrick Maroon's goal.
After reviewing all available replays and consulting with the Linesman, NHL Hockey Operations staff were inconclusive in determining whether the Oilers were off-side prior to the goal. According to Rule 78.7, "if a review is not conclusive and/or there is any doubt whatsoever as to whether the call on the ice was correct, the On-Ice Official(s) will be instructed to confirm their original call."
Therefore the original call stands - good goal Edmonton Oilers.
Since the Coach's Challenge did not result in the original call being overturned, the Boston Bruins forfeit their time-out.