I think I can assist on this . Clearly these twin theorists are influenced by Mark Twain's imperishable account of his brother who may (or may not) have drowned in the bathtub:
Q. ... Why, look here! Who is this a picture of on the wall? Isn't that a brother of yours?Or they may just be remembering Grover Norquist's mandate that we want a government so small it can be drowned in the bathtub.
A. Oh, yes, yes, yes! Now you remind me of it; that was a brother of mine. That's William--Bill we called him. Poor old Bill!
Q. Why? Is he dead, then?
A. Ah! well, I suppose so. We never could tell. There was a great mystery about it.
Q. That is sad, very sad. He disappeared, then?
A. Well, yes, in a sort of general way. We buried him.
Q. Buried him! Buried him, without knowing whether he was dead or not?
A. Oh, no! Not that. He was dead enough.
Q. Well, I confess that I can't understand this. If you buried him, and you knew he was dead
A. No! no! We only thought he was.
Q. Oh, I see! He came to life again?
A. I bet he didn't.
Q. Well, I never heard anything like this. Somebody was dead. Somebody was buried. Now, where was the mystery?
A. Ah! that's just it! That's it exactly. You see, we were twins-- defunct--and I--and we got mixed in the bathtub when we were only two weeks old, and one of us was drowned. But we didn't know which. Some think it was Bill. Some think it was me.
Q. Well, that is remarkable. What do you think?
A. Goodness knows! I would give whole worlds to know. This solemn, this awful mystery has cast a gloom over my whole life. But I will tell you a secret now, which I never have revealed to any creature before. One of us had a peculiar mark--a large mole on the back of his left hand; that was me. That child was the one that was drowned!
Q. Very well, then, I don't see that there is any mystery about it, after all.
A. You don't? Well, I do. Anyway, I don't see how they could ever have been such a blundering lot as to go and bury the wrong child. But, 'sh! --don't mention it where the family can hear of it. Heaven knows they have heartbreaking troubles enough without adding this.