You can view video. You can even download CLEAN video (using extensions like VideoDowmloadHelper) but I believe they use (java) script to view subtitles(subtitles are not built-n). Therefore you have option to turn-of subtitles or select available language for subtitles.
After small research I found out that they hide subtitles in vtt format. I was able to get this file using Chrome Development Tools by analyzing html file in run-time (copy element to Notepad (or any text editor) and and extract src WITH a session variables). Then copy/paste in new window. Is exists any tool/extension which do it (extract this link) automatically?
P.S. The Stream Detector for Chrome return a link to vtt file.
P.P.S The Stream Detector for Firefox do the same. Unfortunately, I installed a wrong extension