It is a small village where residents seem to come into contact with each other daily, so I quite sure he could do some gentle investigation without being too obvious. Presumably he has urged Tom to get her to come and see him, and when she does not he may become -suspicious. Did Belle not see Manpreet recently. She also saw her mental health team about getting pregnant, so that should raise some alarm bells, if she is as bad as Tom says. I still think Tom is taking a risk with his strategy.