What is the structure of N4O, where the 3 nitrogen bonds have different bond lengths and the N=O bond is a double bond. I just don't get it

Answer 1

http://onlinelibrary.wiley.com/doi/10.1002/anie.199316101/abstract

Answer 2

This implies that the double and triple bond are adjacent to eachother, so that would give the N an expanded octet of 10 electrons, but I thought that only happened after P?