49ers coach Kyle Shanahan explains viral sideline exchange with Brock Purdy, who yelled at him during game

Brock Purdy's sideline shout at Kyle Shanahan went viral, but the San Francisco 49ers coach says a helmet communication cutoff was the real issue.

Brock Purdy's sideline shout at Kyle Shanahan went viral, but the San Francisco 49ers coach says a helmet communication cutoff was the real issue.