I agree with former NHL on-ice official Kerry Fraser, I was surprised that this goal wasn't overturned by the war room. The goalie needs to be able to make a save. In this instance, Michal Neuvirth was interfered with and unable to make a save. Below, is the NHL goalie interference rule.
Rule 69 – Interference on the Goalkeeper
Goals should be disallowed only if: (1) an attacking player, either by his positioning or by contact, impairs the goalkeeper’s ability to move freely within his crease or defend his goal; or (2) an attacking player initiates intentional or deliberate contact with a goalkeeper, inside or outside of his goal crease. Incidental contact with a goalkeeper will be permitted, and resulting goals allowed, when such contact is initiated outside of the goal crease, provided the attacking player has made a reasonable effort to avoid such contact. The rule will be enforced exclusively in accordance with the on-ice judgement of the Referee(s), and not by means of video replay or review.
So, if you read the NHL's rule 69, was this the correct call? I don't believe it was.
I'm not surprised challenge did not reverse Det goal. Neuvirth's glove positioned outside paint. Helm's back to net engaged w/Gudas.
— Kerry Fraser (@kfraserthecall) January 18, 2016