There is actually times where the download option for videos is incorrect at R18
I noticed sometimes the downloadable version tops out at 4000 but the streaming version is the full 6000 - you can still download the 6000 version if you change the download link manually.
I assume this program doesn't look at what versions are listed, but just tries different qualities starting at 6000 and lowers it until it gets a match, is that correct?