Cassius Dio
In general, Cassius Dio does not use the word "Christian" in his "Roman History", and appears not to distinguish (or unable to distinguish) Jews from Christians. Given this viewpoint, the large Christian population in Rome that Cassius Dio witnesses in his own time (up to AD 229) would appear to him to conflict with any historical reports of massive Jewish expulsions, such as that of AD 41, thus providing the reason for Cassius Dio convincing himself that Jewish expulsions had not happened.