What has happened here?

Very happy with girlfriend of 18 months.
In the process of divorce from my wife. We split in April 2018.
Today my soon to be ex wife called me very upset and angry and said she received a call from a property developer asking about her interest in housing where my girlfriend currently lives (3 hours away. We do not live together as yet.) She said they said she had put her number into the system and requested a callback. She hadn't.
She thinks I did it and that I am playing games. I did not. How has this happened?