Hi vAfotoriporter,
I had a look at the files you sent me yesterday and they confirm my suspicion. The 16:9 image is actually a full sized raw image but with an in-camera crop applied. This is what is rendered as the preview image (that's why you see the image as 16:9 in PM).
Here's where it gets a bit hairy: PM uses the preview image to base the crop information on. LR on the other hand takes the full-size original raw data and bases the crop on that. Hence the fact that the crop turns out differently (PM/LR crops are relative to the width and height). Note: if you crop the original image in LR you'll see there is actually much more image data than the 16:9 render.
This is fixable, of course, but would create considerable effort on Camerabits'-side, they'd have to try to correctly interpret the initial in-camera crop and take that into account when performing a crop on such images. This would be effort only to serve some very special cases. IMO, I think they'd better spend that on other things. Also given that the 16:9 crop (on raw) is actually still the full image, perhaps the best solution is to simply not shoot in that size; it won't give you any real (space) benefit and it does give you more crop freedom later.
(Note: e.g. Nikon cameras also have in-camera crop modes, but these are true crops and are also applied to the raw data)