Football teams have game film and also practice film. A camera (the “eye in the sky”) takes a view of the entire field and all of the players. “The eye in the sky doesn’t lie” (or “the eye in the sky never lies”) means that the game film shows exactly what happened—both the good and the bad.
 
“The eye in the sky doesn’t lie” has been cited in print since at least 1973, when the term was used by football’s Philadelphia Eagles.
   
   
23 July 1973, Philadelphia (PA) Daily News, “‘The Eye in the Sky Doesn’t Lie’ About Tiner” by Jack McKinney, pg. 49, col. 1:
Ralph (Tiner—ed.) also thinks it’s a great help further to be able to review his own progress in the Eagles’ daily film reruns of practices.
 
“We have a saying here,” Tiner explained. “The eye in the sly doesn’t lie.”
 
26 September 1978, Rochester (NY) Democrat and Chronicle, “Pascarelli,” pg. 5D, col. 4:
Miamia *2-2) running back Del Williams explaining his running problems against Philadelphia (2-2): “We’ll have to wait to see the films. The eye in the sky doesn’t lie.”
 
10 August 1984, Washington (DC) Post, “Redskins’ Nonchalance for Raiders Has an Edge: Raiders ‘Nothing Extra,’ But Memories Are Fresh” by Gary Pomerantz, pg. F2, col. 6:
“People who don’t believe me just have to look at the game film. The eye in the sky doesn’t lie.”
(Washington Redskins wide receiver Charlie Brown.—ed.)
 
13 December 1986, Los Angeles (CA) Times, “Townsend Set for Round 2 With Chiefs” by Mark Heisler, pg. C12:
“All I’ll say is the eye in the sky doesn’t lie.”
(Brad Budde.—ed.)
   
23 November 1987, Sun Sentinel (Fort Lauderdale, FL), “Collapsing Dynasties Are Each Other’s Equal” by Steve Hummer, pg. 1C:
“I turned into the defensive back,” said (Miami Dolphins wide receiver Mark—ed.) Clayton. These days, everyone must play all roles.
 
“I didn’t sweat out the replay. I saw it all the way. And the eye in the sky doesn’t lie.”
       
4 August 1999, St. Petersburg (FL) Times, “Training Camo” by Roger Mills, pg. 7C:
QUOTABLE
“The eye in the sky never lies. When you think they missed you, they’ve got you from both angles.”
- defensive tackle Warren Sapp on performing under high-perched video cameras.
 
Google Books
Find a Way:
Three Words That Changed My Life
By Merril Hoge
New York, NY: Center Street
2010
Pg. ?:
“The eye in the sky never lies” was a common phrase heard during films. We reviewed each play from two different angles: once from the sideline angle we called the “all 22” because you could see every move by all twenty-two players on the field, and again from the end zone angle. What might have been missed in the game was no longer hidden in films.
   
Twitter
Jaylen Kelly-Powell™
‏@JKellypowell
The eye in the sky never lies. Film can be your best friend or worse enemy.
9:34 AM - 19 Aug 2016
 
Twitter
Coach Couture
‏@CompGirlsHoop
Great first game. Got a ton of guys on film. The eye in the sky doesn’t lie!
11:21 PM - 9 Sep 2016