Is it my fault that my girlfriend's son died?

I(56 M) have been dating this woman(53 F) for three years. We've been living together for a year and I couldn't ask for a better girlfriend. I've been married and divorced twice, no kids, so I was somewhat shaky about entering into this relationship, but so far, I don't regret it at all. About a month ago, while we were both at home, she fell really ill(not specifying for confidential reasons) but I immediately called the ambulance and she was rushed to the hospital. Once she had been taken into the care of the doctors, I called her 23-year-old son to tell him what had happened. I told him exactly what the doctors had told me; that his mother may die that night. He said that he would come to the hospital immediately. He also requested that I text him to inform him of updates while on his way.

Eventually, one of the doctors informed me that she was still in a very critical condition, but that she wasn't in any immediate danger and that she had a chance of survival. I was extremely relieved by this information and I knew her son would be too, so I called him to tell him what I had just found out. However, he didn't call back. This really worried me. He didn't live very far away from the hospital, and should have arrived at this point. I called his home-phone and his 22-year-old girlfriend, whom he was sharing an apartment with, picked up to tell me that she had just been informed that he had just been killed in a crash while rushing to the hospital.

After I hung up, the doctors allowed me to go into my girlfriend's room to tell her what had happened. She didn't cry, but it was clear that she wanted to die right then and there. She told me to start planning her son's funeral, and that she wanted to be buried next to him. I told her to hang in there and to not give up hope.

Over the course of the next 2 weeks, I started arranging his funeral, and I visited my girlfriend on a daily basis. Luckily, her health was improving and at the end of the 2 weeks, she was in good health again and was able to come home from the hospital. We held his funeral two days later; his mother stood over grave and said that she would never forget the fact that the last thing he had done was rush to her aid.

While I'm ever-so-grateful to have her home again and in good health, it just isn't the same. There's a hole in our relationship that will never heal. And it's undeniable that had I never called my girlfriend's son, he wouldn't have tried to rush over to the hospital and would still be alive. His girlfriend is now living with us since she can't afford the rent for her apartment all on own, and she's also really empty. And it's all because of the phone call I made. If I had just waited to see with the situation with my girlfriend really was before calling him, her son wouldn't have died.

Neither my girlfriend nor his girlfriend blame me, and my girlfriend isn't having suicidal thoughts anymore. In-fact, she said that was quite thankful that she survive her illness. Do I really deserve to be forgiven this easily and still be loved by my girlfriend?