I'm going to throw this out there only because this is based on my own experience with psychics and based on my own intuitions..... it is possible another woman's energy was no picked up because of where she is in his energy field. How close she is energetically. Not physically. Meaning she could mean jack squat to him really on any level and it will not be picked up. Some people have others in their lives for the sake of having someone, to not be alone, and I feel this is weak, but this is where they are at in their journey. Maybe they need to learn to be alone and only the universe will see to it. I think people have meaningless relation after meaningless relationship in an attempt to fill a void that can never be filled that way.
I hope that makes some sense. Confusing, I know.
This makes a lot of sense, and I think too it depends on how a psychic actually reads - like let's say a person who mainly reads energy, reads a guy and the way his energy feels toward other people shows that there's nobody really important to him that is in his life. He could still be dating some person and just not really have any serious feelings for them, so it might come across in his energy as platonic or unimportant and a psychic would still be right in reporting back that nobody is that important in his life right now so it isn't a stretch to think that they'd interpret that as not dating anyone.
Like for me, I am an empath and can also pick up on peoples' energy but if I'm reading strangers, especially at a distance, their energy gives me a broad overview of a situation. Like if I tune into someone's energy I can pick up are they anxious, upset, happy, sad. Or if I tune into a relationship I can pick up calm, rocky, etc. Broad feelings. But I'm not a mind reader. Other peoples' gifts may work differently or better than mine, but that's how I perceive things when I try to tune into pure energy.