You assume he was tortured. We have that only on his word. Could there be other reasons for coming back to the USA?
Benghazi was a failed attempt to accomplish something, ie, an exchange of the Blind shiek for Amb. Stevens, but there was a double cross.
Maybe this was the second attempt to trade away high value detainees for something.
They wrapped Bergdahl in the flag, and tried to make it look like an amazing triumph for Obama when it was simply a convenient cover to allow five high level enemy back into circulation to continue their mayhem.
The tell was when Rice said that “Bergdahl served with honor and distinction” a blatant attempt at Jedi mind control, not unlike the whole Benghazi video lie.
After all, a lie becomes the truth is you see it often and loud enough.