There is no way to figure them out. I would venture to say that he knew someone would tell you he had been there and brought the ow. He is most likely trying to get a reaction out of you.
When in replay, they have a tendency to go to places that are familiar to them, i.e., places where they use to go w/us and he wants to share that memory with the ow for now. They tend to go on vacations and visit the places we visited w/them, participate in activities that we use to share w/them, etc. It's all part of his journey.
For now, I wouldn't put too much stock into what he is doing. The only thing I would caution you about is...do not react to this recent activity. He got what he wanted...someone told you about the visit. Just let it go. Keep the focus on you.
