FWIW, I think the officials got the original call on the ice right. It's tough, but if you blow the play dead immediately every time a guy looks hurt, you're absolutely going to run into a situation where a guy fakes the serious injury to draw a quick whistle... I think the rule as it is, is fine. If there's a threat for a scoring chance the play stays live until either that scoring chance is dead or the defending team gets the puck.
Where I have issue with the call is exactly what Toews said. Kelly literally did nothing, he didn't initiate the contact with Benson, he was just skating through the blue paint and Benson pulls a late move to try and slip his defender... And of course Kelly wins that battle and knocks the tiny guy down.
IMO it should have been no goal due to Goalie Interference and I really think had they looked at the review longer they would have saw what Benson did and how Kelly didn't initiate the contact at all.