I'm on a PC. I got word back from panasonic - I believe it likely has to do with the sub-sampling employed in the jpeg conversion. Panasonic only supports the following. Image resolution is within constraints. I still have yet to validate the sub-sampling. It's honestly nothing I've payed much attention to so far with my photo work. Since my brand new laptop just got shipped back to B&H for freezing I probably won't be able to test until next week. I'll update with what I find but I'm guessing it's the sub-sampling.
Sub-sampling - 4:4:4, 4:2:2 and 4:2:0
Image resolution - 8 × 8 to 30,712 × 17,272 pixels