Actually as Dr. is a time traveller he could easily come into contact with the Master in one of his previous incarnations....
Oh, and from the point
I love Paradoxes....
Oh, and from the point
from whose point of view? Is it only once the Gallifreyan's know about it or is it once it has happened to anybody - which turns the timelords into observers only in EVERY case - it would probably mean they couldn't raise a hand to help themselves if someone somewhere knew they had been destroyed...One of the things I have to meantion is, one of the key laws of a time lords is not to medle in time once it has happened
I love Paradoxes....