Was the personal phone to be used for work? If not, not such a big deal.
Contrarily, if that influenced the hiring manager’s choice, why say so on the record in the age of everything-ism and cancel culture? Just hang up and move along.
[Was the personal phone to be used for work?]
If it’s the phone number she gave on the application/resume, it’s a work related call. Recruiting calls and interviews are still business transactions.