You don't need to have a valid registered trademark. A registered mark only serves to increase your capacity to defend your trademark. A Common Law mark is sufficient within the US which specifies first to use and first to market. HOWEVER, that doesn't change the fact that we may be looking at trademarks within 2 different countries AND it still in now way changes the fact that the guy is attempting to claim copyright on YouTube videos for a Trademark dispute. Which is still illegal.