So what is the connection between the GPS points and the cell triangulation? How does having the cell triangulation data lead to having the GPS points? The parent claims the providers can magically access the GPS receiver in the handsets. But they really cannot, so the providers only have coarse data that cannot be used to track people on this level. The data is from another source, not the provider.
It’s much more likely the user agreed to install an app that is recording his location information.