CBS showed an impossible view of the fireworks over Fenway as part of its Fourth of July broadcast. (Images from YouTube)

The only problem: the fireworks display was fake.

Yesterday, viewers began to point out to the Boston Globe that the display CBS broadcast included views that were geographically impossible, since the fireworks display was launched from a barge in the Charles River in a direction away from those landmarks.

David Mugar, the Boston-based executive producer of the show for the last nine years, confirmed Thursday that the footage had been altered, for the first year ever. Mugar said the network’s actions were justified because the show was entertainment and not news.

“Absolutely, we’re proud to show scenes from our city,’’ Mugar told the Globe. “It’s often only shown in film or in sporting matches. We were able to highlight great places in Boston, historical places with direct ties to the Fourth. So we think it was a good thing.’’

Mugar insisted adding footage of the landmarks shot weeks ago to the fireworks display was no different than the TV producer of “Boston Legal” using scenes from Boston even though the show was shot in Hollywood.

In preparation for the show, Boston camera crews shot footage of the Old North Church, the State House, Quincy Market, the statue of Paul Revere, and Fenway Park, among other landmarks.

“And we did it all with the intention of superimposing the fireworks over the images,” Mugar told the Globe. “The technical process is called matting.’’

Boston natives weren’t too pleased with Mugar’s explanation.

Nearly 80 percent of those who read the Globe story said it bothered them that CBS faked portions of the show.

T.J. Jeffers, a Boston resident wearing a Celtics T-shirt and Red Sox cap, told the Globe, “It’s one of the biggest times of year here. ...The fireworks, the crowds. It takes you back to your childhood. ... But I’m shocked they changed stuff on TV, because they didn’t need to. The fireworks don’t need dressing up. They’re fireworks.’’