Site-menu docs possible issues

I may be misunderstanding but it looks like there might be a couple of issues in the site-menu documentation and demo:

https://github.com/bbc/gel/blob/master/docs/components/site-menu/index.html line 144. I found the "hidden" here confusing as I don't think it's part of the initial HTML, but is instead added by JS, and it's important that it isn't there if JS is disabled.
https://github.com/bbc/gel/blob/master/docs/components/site-menu/index.html line 128 the span ID doesn't match the aria-labelled-by on line 127
https://github.com/bbc/gel/blob/master/_content/components/demos/site-menu.html line 7 same issue with IDs

bbc / gel