I receive the Scottish equivalent and the experience could not be more different than my friends description of his encounter with the PIP process. The Social Security Scotland staff that I interacted with throughout the process genuinely seemed to care about me. Someone came to my home to help me with my application and assisted me in writing it in such a way that I'd get as much help as possible.
I have another friend who works with Social Security Scotland and he says that going after fraud is such a tiny fraction of the work he does. I personally agree with that philosophy, its worth accepting that some small percentage of fraudsters will slip through the cracks to make the process as smooth and comfortable as possible for those that truly need it.