I think they might sent him a file that contain malware, told him to open it. He trusted them
I expect he should have some level of paranoia towards opening sent files from unknown source. Well he's same person that had 150 address holding approximately a million in a single device.
150 wallets and all on the same device? I would not be surprised if he was advertising himself as a privacy and security expert, what an idiot. 
Not everybody listen to their own advice. Knowing the right thing is one thing but doing the right thing is another.[/quote]
If not because I came to this forum, I did not know all these. It was when I came to this forum that I started to know about scam and hack and how they are working. Also this forum helped me to know about each wallet types and their importance and how our devices can download malware. This forum helped me a lot. But there are some people that do not learn about scam and hack and also do not have a forum or community that they can discuss something like that, that is why you will see them vulnerable to scam and hack.