Incorrectly changed title case

[Joseph_Reagle]

Hello all, when I use the following YAML entry with chicago-fullnote-bibliography.csl the title is rendered as:

“The IKettle, the Eleven-Hour Struggle to Make a Cup of Tea, and Why It Was All About Data, Analytics and Connecting Things Together,”

Because “iKettle” is a mixed-cased proper noun, it should not be changed IMHO. Is this expected behavior? Is it the result of the specification, actual CSL, or citeproc? Any tips appreciated.

pandoc 1.19.1
pandoc-citeproc 0.10.3—
references:

• id: Rittman2016ieh
  type: post-weblog
  genre: Web log message
  author:
  • family: "Rittman"
    given: "Mark"
    container-title: "Medium"
    issued:
    year: 2016
    month: 10
    day: 12
    title: "The iKettle, the eleven-hour struggle to make a cup of tea, and why it was all about data, analytics and connecting things together"
    URL: "https://medium.com/mark-rittman/the-story-behind-the-ikettle-the-eleven-hour-struggle-to-make-a-cup-of-tea-and-why-it-was-all-769144d12d7\#.au2p9rjbz"
    accessed:
    year: 2016
    month: 10
    day: 17

…

[Sebastian_Karcher]

I think the specs (and citeproc-js) have this right:
The iKettle, the Eleven-Hour Struggle to Make a Cup of Tea, and Why It Was
All about Data, Analytics and Connecting Things Together.

This follows the 2nd sentence of point 2. here:
http://docs.citationstyles.org/en/stable/specification.html#title-case-conversion
So I think this is a citeproc-pandoc bug.