Board Thread:Boruto Discussions/@comment-32586725-20170715185225/@comment-734582-20170716082051

Mr. Grave wrote: In episode 14, Boruto's eye somehow transferred the Nue back into its home dimension the moment Boruto clashed with Sumire. In episode 4, Boruto tried to use the Summoning technique without a blood contract in Sumire's presence. The Nue couldn't leave it's dimension once Sumire lost the Gozou. Suggesting that it's existence in it's own dimension is it's natural state. Whatever happened exactly, it seems that Boruto broke Sumire's summoning, reverting it back to the natural state.

Mr. Grave wrote: caused the Nue to emerge, but because at that point it hadn't gathered enough chakra, then it couldn't appear in its complete form. It seems the Nue needs chakra to manifest properly in our world, but not in his own. It appeared noticeably bigger in our world after it got a lot of chakra, but it was quite small in it's home. Mr. Grave wrote: A more specific theory states that because Boruto's dojutsu enables a connection between him and Nue's homeworld, then smearing his blood on the scroll without a contract with another summon automatically spawned Nue. I find this unlikely, we've been told repeatedly that Spacetime ninjutsu creates user-specific spacetimes. If Boruto can enter Nue's spacetime, that implies a connection to the Nue. I find it more likely that Boruto was somehow affected or infected by the Nue's chakra due to his encounters.

We've seen with Edo Tensei that minimal information can summon even souls, so as long as Boruto tried to create a contract while contaminated by even a little of that Dark chakra, he could've summoned it.