Rambam, Laws of Repentance II

From the verse: "Is this not a complete repentance? He who comes to him with something that he has committed, and it is possible for him to do it, and he explains it and does it because of repentance, not out of fear or lack of strength. How? Then he who comes to a woman in transgression, and after a time has intercourse with her, and he stands by his love for her and the strength of his body, and in the state in which he committed it, and explains it and does not commit it, this is a complete repentance."

There seems to be a contradiction here, since the same person transgresses the prohibition of separation. Maimonides explicitly says "we separated ourselves," and does not distinguish whether we separated ourselves intentionally or accidentally. How is it possible that he committed a transgression on the one hand, and on the other, he made a complete repentance?
If you come and say that these are two different offenses, there is a contradiction here with Halacha B. It seems that if "we separated ourselves" apparently does not meet the definition of "and removed from his mind" (there is a reason for us to separate ourselves intentionally) according to the definition in Halacha B, it seems that not only is there no complete answer here, there is not even a basic answer here?
How do you explain this?