I was just talking about this to someone else on facebook.
Ghosting is very common unfortunately. Not just in dating but friendships and job interviews too.
Confronting the other person doesn't do any good. I did it recently.
Ghosters usually don't care if they hurt you or not. They've deemed someone or something else more important. This is why confronting them won't really do anything, It could get the person to do introspection on themself, but usually isn't the case.
We're so used to social media and being behind technology that people in general lack humanizing people. We forget the other person has feelings, emotions, and stuff going on. We only consider what is best for us, even if it hurts the other person.
Ghosting is a very childish thing to do. If you can't tell a person, something to the form of, "Thank you but I'm not interested in pursuing this further, I wish you the best". You shouldn't have a managerial position or be dating.
Job related wise. I interviewed for a position at a financial institution in Des Moines about 5 years ago. I completed the interview and they said they'd keep in touch. They said they were still working on interviews. Another month, told me I was a finalist and they were preparing final interviews. I didn't get a rejection email until 6 months later. I forgot about the job at that point, but I will never do an interview with that company with the lack of professionalism they displayed at the end.
A mature person will not ghost someone they know has feelings for them. The best thing you can do as a friend is listen to them vent. It sounds like your friend didn't do anything wrong. The world has a lot of emotionally immature people and ghosting makes it easy to spot these people to not involve in your life. Let your friend know he's not alone, this happens to everyone.