MONTREAL — As linesmen Kyle Flemington and Trent Knorr continued to squint at the tablet being held up to their faces, Bruins coach Bruce Cassidy knew the call was not going his way.



“They’re over there for three minutes,” Cassidy said of the linesmen’s extended peek at whether Charlie Coyle was offside prior to his would-be go-ahead goal. “What is the purpose of this rule? Either you find something you don’t. Three minutes. Now you’re looking for something, for it to be offside. You know it’s going to go the other way, and it did.”



The reason Flemington and Knorr burned through so much screen time is that they were searching for a needle in a haystack. In that instance, Coyle might have crossed the offensive blue line before the puck. But if he did, it was by a fingernail’s width.



And that is Cassidy’s problem with the rule.



“There was a change this summer, punishing the...