Mozilla also does this for Firefox, and I think it's fairly important actually. When you go to libreoff.org from Aus/NZ it should download the GB locale by default, not US. We speak use GB spelling. I have no idea where this request should be made.
Here is the response that I got from our Infra team about this - setting to NOTABUG because it's not :) "only if there'se NZ or GB in the user's browser string. It doesn't do region matching, but does pick according to the users preferred languages. Show source of the DL-page and there'll be a comment that shows the user-agent string and what guesses the site made based on that. (line 129 or so)" So it looks like it'd dependent on settings you have in your browser, LibreOffice does not guess based on region instead it goes by your browser settings. Hope that helps - if not I encourage you to ask on the user mailing list for help.
Sorry I've been away so only just got to this, but I'd like to make some more comments. I opened a stock instance of Chrome, I go to libreoffice.org and click the big download button on that page. It starts to download: http://ftp-srv2.kddilabs.jp/office/tdf/libreoffice/stable/4.4.3/win/x86/LibreOffice_4.4.3_Win_x86.msi Also the default Help pack link is: http://ftp-srv2.kddilabs.jp/office/tdf/libreoffice/stable/4.4.3/win/x86/LibreOffice_4.4.3_Win_x86_helppack_en-US.msi Clearly showing it's en-US for the Help pack. I installed on a fresh computer with Typical settings, then opened Writer and wrote some words with British English spelling "armour, colour, licence, penalise" etc. That all works, and About Libreoffice shows an AU locale, as is set in all places in windows 7. However, it's still an issue for the Help files, but that seems to be written about here: https://bugs.documentfoundation.org/show_bug.cgi?id=39325 So, the helppack at least is being downloaded incorrectly.