using it in a video, you should be good. mr.bumpy apparently didnt care (as few really do) otherwise he would have changed the credits to include his name, as-well as Ivo's Though if you want to re-distribute i would suggest including his name somewhere on the page
in reality most people dont care to much about copyright usage, aslong as your not trying to make money directly off there work (IE creating a commercial product, and bundling the skins with it)
the absolute worst that would happen, is you get a message from him asking you to stop, and i cant say ive ever seen that happen