I don't currently have a Dime account so I can't see that linked page, however..
The simple answer in this case is that there is no direct correlation between files size and sound quality. The files are slightly different sized empty containers which we can fill with whatever- good quality audio, crap audio, or with silence. We can make a great sounding 16/44.1 WAV which smokes a 24/96 WAV, just by doing a better job of recording and putting much that better quality audio into that 3.5 times smaller container. The good quality audio will fit within the smaller container easily. The ultimate limits imposed by the bit depth and sample rate in this case is certainly not relevant (and is negligible in most cases).
But to address your actual question-
What exactly is 80MB smaller? the total file package? Presumably these are FLAC data compressed files and the data compression will make the file sizes different, even if they are both 16bit/44.1kHz WAV files and happened to be exactly the same size uncompressed. But the uncompressed WAVs are unlikely to be exactly the same size even if they are both 16/44.1 file sets, simply because the two file sets were tracked slightly differently by different folks, so each file and each entire set will not be exactly the same length.
In addition there could be extraneous data appended to the original WAVs, such as recorder manufacturer specific data. For instance, file markers made on the R-44 fall into this category. TLH removes that from the WAVs when FLAC compressing unless the Keep Foreign Metadata box is checked (I tell it not to strip that info when I compress my raw masters so I retain those markers in the FLAC'd but untracked master).
Beyond that, there could be different metadata in the two different FLAC sets, usually tagging info, but it could be anything, like photos.