I'm not convinced

Just watching this movie for the first time. To be put in the shoes of the lead character, Thomas Archer, who's son was murdered and wife beaten. Then to be put in a sealed room with the alleged killer strapped to a chair and a bunch of pain-inducing tools on a table. An encrypted voice on a phone says this is the guy and I have the opportunity to pound the man and "get revenge". Even if I was totally bent on said revenge, I'd need to know beyond a shadow of a doubt that this really was the guy, but in the movie Thomas Archer just starts wailing on him, and then woops - starts wondering if it's the wrong person. Pretty messed-up psychological experiment IMO which doesn't convey empowerment to the protagonist. Also, the guy in the chair seemed pretty lucid and unaffected after being beaten up so badly. Again, unconvincing.