Seeking advice: 15 year old gay I don't want him out in the cold

I have a female coworker. We're friends. She has a 15 year old gay son. He's fairly recently come out. She says she accepts that he's gay and doesn't care that he's gay. She has times when they're just struggling with each other. She tells me everything that's happening in her life. She's a Pisces. As is he. The most recent thing thats happened is that they were arguing and she told him she can't deal with his bullshit anymore and she told him if he wants to leave that he can leave. So he left. And soon after he left she started to worry about him and thought something bad night have happened to him because she heard sirens. So she called the cops. I'm just confused as to why she told him to leave and then called the cops later. He's on probation for being allowed to be served alcohol and being a minor. He's also been missing school. She had a surgery and couldn't find anyone to pick her up or be with her during the surgery. She was mad at her son because he's learning to drive and she wanted him to be there for her and then drive her after. And he went to school. Or so she thought. Only later to find out he skipped the second half of school that day. I haven't talked much to him. I only hear what she tells me. I personally want to talk to him and hear his side of the story. Of everything. So back to him leaving the house and her calling the cops. She says she was worried about him so called the cops. The cops went to all his friends houses looking for him. They didn't find him. Apparently none of his friends could provide him Shelter. So the cops found him at a park in town. I remember that night. That night was a very cold night. So it hurts me. Thinking he was outside in the cold. But I had no clue any of this had happened. She's told me this after the fact. So all in all I don't know what to do. I need advice. I want to tell him on facebook that if that ever happens again that he can stay with me. I don't want him out in the cold. Or feeling like he has no where to go. Any advice would be most helpful.