Salford trailed 20-18 when Stuart Littler tapped down another Bobbie Goulding `special' and Gibson thought he'd grabbed the winning try in the corner.
But action man Adam Hughes popped up from nowhere to pull off a match-saving tackle with the video ref controversially ruling Gibson had been bundled into touch.
Dejected coach Steve McCormack said: "Damian was convinced it was a legal try and another couple of decisions went against us.
"Widnes had two tries disallowed but Damian's was a real sickener."
"At least, it was a big improvement on the Castleford performance and youngster Michael Platt did well on the wing. But effort isn't enough to win matches."
Platt, 18, was a surprise inclusion in place of Nick Pinkney with Greg Ebrill, Danny Arnold and Graham Holroyd also out after the 74-16 horror show against the Tigers. Goulding worked overtime against his old club, landing four goals from five attempts and also setting up a try for Darren Treacy when Jason Demetriou spilled his towering `bomb.'
Goulding believed he had secured a much-needed victory for Salford with his penalty when he was obstructed by Robert Relf to make it 20-18 with 12 minutes left.
Then Relf charged over with Hughes tagging on the goal.
Hughes' contribution was immense with four goals, a try, a disallowed effort and that wonder tackle on the impressive Gibson.
Coach Neil Kelly said: "Adam is a future representative player and that tackle was just as good as Keiron Cunningham's on Mark Smith for Saints against Wigan recently.
"We're now fourth in the table but will keep our feet on the ground and survival is priority."
Salford have only themselves to blame for another defeat.
They led 12-2 with tries from Mike Wainwright and Littler with only four minutes to go before the break.
But then the dozy Reds allowed Daniel Frame to take a quick tap penalty and score before his crossfield kick led to a Jason Demetriou try.
Those slips proved fatal with Widnes going ahead 14-12 at the break after being 12-2 down.
Salford certainly had the better of the first half. Tweet