Is this the right advice?

My boyfriend about a month ago met a friend of his that he had kept in contact with via email for some years. She didn’t live here but moved over to study for the year. I knew about her as he had mentioned her a few times. Anyway, despite the seemingly close contact she never said she was actually here in the country. It was 3 months before she even emailed him. My boyfriend found this a bit strange as he had sent a couple of emails to see was she settling in okay but got no response. He had given up on her responding and then out of the deep blue he heard from her. He decided to meet up with her but I wasn’t able to make it. This is where things go perculiar, he said when they met she didn’t seem to be interested in talking, was looking around and acted nervous, almost as if she didn’t want to be there. There should have been lots of things for them to talk about. Then, this is where the ultimate twist is, he left the table to go to the mens room and came back. She said she had to go, so he went to pay, when he took out his wallet (which was in his jacket on the seat when he went to the mens room) he discovered no money in it. He said it to her that his money was missing and what he found strange was that she never asked how much was missing. Anyway,they left and went there separate ways.Afterwards he was telling me and I found it strange. He now suspects she may have taken the money as it couldn’t haven’t been the individual sitting with his back to him at the table, why would that person put my boyfriends wallet back in his jacket if he went to take it,he could be seen putting it back. He feels she may have taken the money when he went to the mens room. He feels awful though for suspecting her. My own thinking is that if she was a genuine friend she would have been more concerned and at least emailed a few days later or even a couple weeks later to see if he ever found the money. He doesn’t want to say anything to her about it and my advice to him was to see if she comes back and says something. It was his money that went missing and she should be concerned. So far though nothing. He feels very let down by this friend and I hope my advice is right.