Broncos' video director Steve Scarnecchia taped six minutes of the 49ers' practice, against league rules, in London on October 30, the day before their game at Wembley Stadium, the NFL said.
Scarnecchia gave the video to McDaniels, who did not watch it but because he had not reported the incident had breached league policy, the league said in a statement Saturday.
The Broncos were fined because clubs are "ultimately accountable for the actions of their employees," the NFL said.
Broncos executives were made aware of the incident on November 8 following the team's return from London and after an internal investigation contacted the league four days later, the NFL said.
Scarnecchia has since been fired by the Broncos.
