Well, this is just my own personal experience, and you guys are free to do whatever you like, of course (and it goes without saying, that I am in no position to speak for Stef).
But, by hacking out the branding visuals at the beginning of each video, and only offering one short two-second reference to FDR at the end, it makes the videos look like - at least, to me - someone else's (namely your) work.
It's one thing to offer German translations of Stef's work (and even to display them prominently on your site). It's quite another to completely re-brand it all under another logo, and only reference the originator (Stef) as a mere advertiser on your site.
Does that make sense?