I really don't feel concerned about the friend not being named. I'm an extremely private person and would not feel that information (the name) was pertinent to the public..the police certainly know who he is and what the relationship is. I also don't feel it is unusual to have other friends or relatives along on a camping trip. It's not like a hotel where you have to pay for everybody.
Also, trust me on this, 72 does not equate to a sickly, doddering, old man. My mum died a month age at 87, unexpectedly, but peacefully, in her sleep. We had spent the previous weekend at a friend's cabin in the mountains and she walked, etc. with us with no problems. While I wouldn't have asked her to baby sit, she helped take care of her young great-grandchildren into her late 70's without missing a beat.
I would respect a friend's privacy in this type of situation, and would like mine to be respected in this type of situation. I wouldn't hesitate to help police, etc., but definitely would like to keep things private.
I have been in a situation where a reporter has tried to interview me about something very personal to me. This person never respected my privacy, and continues to pop up now and then. He contacts my friends, etc, My friends refuse to talk to him, but he persists. He shouldn't even know my name but someone gave it to him and he thinks that gives him permission. Why should the friend's name be out there at all if he has nothing to do with this?
Just IMO and all that!