Interestingly enough, I notice the guy has a few Retro Core clips from the DC Shooters Special in his video list.
He doesn't seem to come out and say "I MADE THIS", but he also doesn't make any mention of where they originally came from. Haven't watched through all of the final clip to see if he cut out the credits from the last part. Would be nice if he had mentioned yourself and your site in the descriptions though... :edit: Credits were still present in the final scene.
hmm, I can't be arsed bothering to be honest. I'm sure more people have seen the Retro Core homepage than his videos to know where they are from Yakumo