Versus, which carries the bulk of NHL games in the U.S., said it was looking into what happened to the Dallas-Vancouver game in some regions.
"Versus has received reports that last night's Dallas/Vancouver game was switched to an infomercial in the fourth overtime," the network said in a statement. "We are obviously very disappointed to hear that some fans in a few select markets have reported that they did not see the end of this great game.
"The game did run in its entirety on the Versus network feed, but based on the information we have received we are currently working with our affiliates in the affected markets to find out what caused the problem and to make sure that this doesn't happen again during the playoffs."
The game, a 10 p.m. ET start that aired in Canada on CBC, ended at 18:06 of the fourth overtime when Henrik Sedin scored to give the Canucks a 5-4 win in the opening game of the NHL Western Conference quarter-final series.
It was the sixth longest playoff game in Stanley Cup history.