Josh Lasser reviewed The Whole Truth for IGN. He said the following about the cast.
Reeves, Zellweger, and the rest of the cast do an admirable job elevating the characters above their mundane trappings, turning them into three-dimensional beings. In their hands the characters become something more.
He has said the following about the film overall.
…the reveal is not a surprise; that The Whole Truth doesn’t have anything truly special up its sleeve. It is a letdown in a film which is otherwise a tense courtroom thriller. The movie tips its hand just a little too much a little too often, which takes what could be an exceptionally satisfying thriller and turns it into an acceptable one. It is a film which succeeds based upon the acting and sense of tension it imparts, but those elements never work in concert with the story.