I assume that the CTR went off without a hitch, and there are no questions about the source of funds?
I would suggest you consider the possibility that your customer is being scammed, and take some steps to authenticate the home purchase transaction. I would even go as far as reaching out to the customer to say that you are concerned that the customer may be getting swindled and offer to assist the customer in reviewing the documents.
After this research is completed, you'll have a better idea of which, if any, boxes need to be checked on a SAR.