As you're finding out the hard way, it can be extremely difficult to get and interpret medical information about another person"”especially from within the confined walls of a hospital.
It sounds as if you've already taken some important steps in collecting additional outside evidence. Continue to be tenacious.
Lawyers are often unwilling or unable to get involved in such cases if the cause and effect are not clearcut or there is not likely to be a large amount of money involved because of the patient's age or condition. But there are a number of other places you may be able to turn for help.
Every hospital has ombudsmen or patient representatives whose job it is to advocate that patients receive good and proper care there"”and they are also charged with dealing with family members' concerns about the type and quality of medical care. These advocates may also help bring complaints before the hospital's ethics committee or dispute resolution panel to help resolve issues of wrongful care.
If this route fails, register your complaint with the Patient and Family Advisory Council of the Joint Commission at http://www.jcaho.org. Or call 630-792-5000 or send an e-mail to firstname.lastname@example.org.
Finally, consider contacting the agency that licenses and regulates hospitals in the state where your grandfather died. You should be able to find that by doing an Internet search of the state plus "licenses and regulates" and "hospitals."