Personality is merely a term used to describe the sum total of characteristics that make us each unique. We each have a personality which is our style of interacting with our world.
There are, however, _personality disorders_ in which the individual has developed a pattern of maladaptive ways of interacting that results in some degree of occupational and social impairment.
People with a personality disorder do not feel that they necessarily have a problem. They do feel that there is something wrong with everyone else.
The individual you describe may have a paranoid personality disorder. Such individuals, when injured, expect the worst and look for it continually. They hire a lawyer to protect themselves and end up not trusting the lawyer. They anticipate betrayal from family, friends and doctors.
They live in a world where they are defending themselves against others whom they perceive undermines their authority. They attribute to others the very characteristics that actually may define themselves. They believe that others are scheming against them. They feel that they will have to defend themselves, and they cannot readily relinquish control to others.
Once you have had this personality disorder documented, and you are certain that is what you are confronting, then you can establish a clear line of communication. Keep conversations brief and always directed toward the point/topic. Do not respond to accusations because defending yourself will have no positive impact. Anticipate that you will not be trusted no matter what you do and be prepared to document all of your actions.
Be certain that the primary treating physician is aware of this pattern of behavior so that he/she can assure that he does not fall prey to the same chaotic interactions.
Be aware that you will not be successful in changing a personality disorder, but you can learn to anticipate how someone with a paranoid personality disorder does respond.
And, by the way, a personality disorder cannot be caused by injury, but it can certainly complicate your management of that injury.