He's already taken the cognitive process tests, and from what I remember, Ti and Ni were the highest, and then I think Ne and Fe were next. So they were very ambiguous results, and why there was never 100% certainty.
I had mentioned before, that if INFJ, the tertiary Ti would "inflate" itself, to possibly appear dominant (hence, "obsession' with logic). Though he always genuinely seemed like a Ti dominant. A lot of INTP's had come up with strong Ni (I seem to be the only one for whom it is weakest).
If INTP, then Si would be the inflated tertiary. For me it definitely is, though many other INTP's have it as weak. IIRC, it may have been weak for Evan as well. I've more recently been looking at Lenore Thomson's brain alternative theory. I know that this works for the first two processes. Their opposites will come up as "alternatives" when the preferred processes cannot solve a problem. I'm not sure if that works for the tertiary and inferior. If so, then Ni could be a left-brain alternative for Si.
So a lot of it depends on the person's experiences. Even Fe could develop sooner than expected. Even Fi might come up a lot as the right-brain alternative to the dom. Ti. So it looks like the best way Evan can sort this out is to compare the roles Ne and Ni actually play out in his life. Those two mark the biggest difference between INTP and INFJ. (Since it can sometimes be hard to determine whether T or F is preferred, especially when the inflated tertiary or anima are involved). Is Ne like a "good parent" function, or it is more "oppositional", and only backing up Ni. Is Ni heroic, or is it more like a critical parent that also gives wise discovery at times?
I also once suggested ISTP, though it is true that there is definite N over S. But you always did seem more genuinely T over F.