Can a DNA test be court ordered and can the military assist?

The only thing that I have ever known to be true about my biological dad is his name. That is because his name is on my birth certificate, not signed but it reads his name and what state he was from. His age, from what I gather is near 67. Based off what my mom and uncle have shared with me, along with a few other relatives, I did some investigating and researching that in turn led me to one person, who I tracked down and met. He's a Vietnam Veteran and has had some misfortune. He suffered some kind of head trauma and for whatever reason did not get it looked at. From my understanding, he's paralyzed from the chest down. I learned this after I got to spend almost an hour with the man. I asked him some questions, and based on his answers he could very well be my real dad. We spoke and he said he would consent to a blood test or DNA test. I couldn't stay. I had to go back, work and bills, you know how it is. I walked away feeling like I left a piece of me in that room with him. This happened almost a month ago, I have attempted to make contact but I have been informed by a social worker that he and his wife are not wanting to speak with me. I left a copy of my birth certificate, my name, my physical address, my email and my phone number with his nurse. There has been no contact made. I check my emails including spam daily. He did not have any kids and I don't believe he knew about me. With all that being said, what are my rights? Where do I stand as far as his wife is concerned? I did not have enough time to meet or talk with her . If it turns out he is my father, that's what I'm hopping happens, then I can get to start healing process, however if test say he is not my father, can the man sue me or have me arrested for harassing him.