Just so the Star Wars people don't complain 
About the lying. One thing I noticed about Teddy is that for a narcotics officer he is a terrible liar. In times when he is clearly lying he lowers his voice and looks at the ground. One example is at the tattoo parlor when Teddy was saying that it was some other cop fucking with Lenny on the phone. However it seems that when he is telling the truth he looks straight into Lenny's eyes (or into the camera). So I feel pretty confident that Teddy was telling the truth at the end. I could be wrong about this.
Another point that I wanted to make is that although yes a person can respond mental conditioning I would think that the types of memories formed by conditioning would be more instinctive rather than cognescent. So the type of memory that would be formed for Lenny or Sammy would be more like "there's something wrong with me" rather than "this is exactly what is wrong with me and this is exactly how it happened...." Notice that when they were testing Sammy it was for things like shock therapy. I don't think they expected him to know exactly why he shouldn't pick up the pyramid. Instead I think they expected him to instinctively choose another object.
In a way I think it's kind of like blindsite. A person may suffer severe damage to the visual cortex and still be able to instinctively sense if an object is approaching (assuming there is nothing wrong with his eyes), but the said person can't visualize or describe the object.
About the lying. One thing I noticed about Teddy is that for a narcotics officer he is a terrible liar. In times when he is clearly lying he lowers his voice and looks at the ground. One example is at the tattoo parlor when Teddy was saying that it was some other cop fucking with Lenny on the phone. However it seems that when he is telling the truth he looks straight into Lenny's eyes (or into the camera). So I feel pretty confident that Teddy was telling the truth at the end. I could be wrong about this.
Another point that I wanted to make is that although yes a person can respond mental conditioning I would think that the types of memories formed by conditioning would be more instinctive rather than cognescent. So the type of memory that would be formed for Lenny or Sammy would be more like "there's something wrong with me" rather than "this is exactly what is wrong with me and this is exactly how it happened...." Notice that when they were testing Sammy it was for things like shock therapy. I don't think they expected him to know exactly why he shouldn't pick up the pyramid. Instead I think they expected him to instinctively choose another object.
In a way I think it's kind of like blindsite. A person may suffer severe damage to the visual cortex and still be able to instinctively sense if an object is approaching (assuming there is nothing wrong with his eyes), but the said person can't visualize or describe the object.