Hope you are well & actually come back to read this after posting it over a month ago!
Anyone can create false memories- memories are subjective. Even the power of suggestion can create a false memory in someone. A person doesn't need to be schizophrenic in order to have a 'false' memory.
Yet he said he's not schizophrenic? So what has schizophrenia got to do with his supposed past life memory?
TBH, past life memories are very much beliefs of the individual. What he thinks he 'remembers' are obviously a bigger part of his personal belief system. Perhaps, he genuinely believes he knew you in a past life.
Perhaps he's just trying to get you to believe that you're his 'Soul Mate'.
No matter- this is more about his beliefs, rather than his memories.