At 6:18 of the first period in the Lightning/Islanders game, New York requested a Coach's Challenge to review whether Tampa Bay was off-side prior to Steven Stamkos' goal.
After reviewing all available replays and consulting with the linesmen, NHL Hockey Operations staff determined that Tampa Bay's Tyler Johnson was off-side prior to the goal. According to Rule 78.7, "The standard for overturning the call in the event of a 'GOAL' call on the ice is that the Linesman, after reviewing any and all available replays and consulting with the Toronto Video Room, determines that one or more Players on the attacking team preceded the puck into the attacking zone prior to the goal being scored and that, as a result, the play should have been stopped for an "Off-side" infraction; where this standard is met, the goal will be disallowed."
Therefore the original call is overturned - no goal Tampa Bay Lightning.
The clock is re-set to show 13:51 (6:09 elapsed time), when the off-side infraction occurred. Penalty time clocks also were re-set accordingly.
Since the Coach's Challenge resulted in the original call being overturned, the New York Islanders retain their time-out.