Okay so my theory is that the grandma did die and a few days later the puppy died too and that was his last straw. He's lacking a lot of sleep, he's grieving and the mix with alcohol made it worse. He was reflecting non stop on how shi*** his life is and he wants it to end. At the same time the picture was posted by (one of) the nurses or patato just told the other boxers tha he saw Kim Dan and Jaekyung overheard it. Either way he got there asked the grandpa where Kim Dan was and saved him last minute.