This is one of the greatest misconceptions about how interrogations are done. In the Spanish Inquisition and Salem witch trials, the tortured to get confessions. In terrorism interrogations (which do include water boarding and other tactics), the goal is to get information. The information they gather is not treated as factual unless it can be confirmed or corroborated from other sources.
When Khalid Sheikh Mohammed was interrogated, they only asked him questions that they already knew the answers to. They weren't immediately trying to get information. They were trying to get cooperation. Once he started answering truthfully, then they asked him questions for information.
When Khalid Sheikh Mohammed was interrogated, they only asked him questions that they already knew the answers to. They weren't immediately trying to get information. They were trying to get cooperation. Once he started answering truthfully, then they asked him questions for information.