"I'm the Doctor. I'm 903 years old. I'm from the planet Gallifrey in the constellation of Castaborous. I'm the Oncoming Storm, the Bringer of Darkness, and you... Are basically just a rabbit, aren't you?"
The Time Lords had more the one renegade like the Doctor, and the Gallireyan Celestial Intervention couldnt track them all down (thats how many time lords got fed up with the boring hum drum life on gallifrey), so it is quite possible angela is an entirley new time lord we never heard of.