If you'd look at their discussions about the whole Israel/Palestine thing, then you'd see that they both hold very different views on that subject. You'll also notice that I've been rather quiet on that subject in comparison to the both of them. That alone should be solid evidence that we are all different people.
He will say something along the lines of: "But... but... but I have not said THE SPECIFIC WORDS ______________". IOW, he rejects deductive reasoning when convenient in the same manner that you reject set theory when convenient.
That's fair. Nobody sees every single post that occurs on this forum. However, if you take a gander into pretty much any Israel/Palestine related thread, you will probably find several back and forth posts between IBD and ITN in which they are in strong disagreement with each other.
You can also dig up some accounting-related posts between IBD and myself in which we both clearly disagree about some particulars (even though we are in agreement on most aspects).
You can also dig up some posts on the subject of Christianity. IBD is a self-proclaimed atheist (not to be confused with the religious belief that God does NOT exist) while ITN and I are both self-proclaimed Christians. ITN and I do attend churches of differing denominations (there's MANY different ones out there, and some churches are even non-denominational) but as Christians we both share the same core belief that Jesus Christ exists and is precisely who he says he is.
ITN is from Washington, I'm from Wisconsin, and IBD is from Maryland (I think?).
One could go on, but I would think that this is a good bit of evidence that we are different people.