As an EMT (mandated reporter) I would be required to file paperwork and report this to the state as elder neglect, allowing some one to live in unsanitary/dangerous conditions. Mandated reporters ( EMTs, Police, School officials, and others) are legally required to report elder abuse and neglect, child abuse and neglect, and domestic abuse to the department of social services , and could face serious cosequences if they don't.
As a firefighter I would hope that anyone who came upon this type of situation would take the same action as the OP, and not make me risk my life to go into this structure and pull out a 70 year old man trying to live the "american dream of freedom". We need to remember that this isn't just a case of letting someone live however they want, there are building codes, health codes, and fire codes for a reason. To protect the public at large, and in cases like this specifically emergency workers.