We had a number of people that flagged the game Top Defense for not working. Our team looked into what was causing this and the main issue we found was that the game was attempting to load something from a URL that is no longer around.
Unfortunately, we could not resolve this independently so we have had to remove the game from our site.
1) Have you tried to reach the devs?
2) This sounds like something you could work around by making the faulty URL point to a placeholder resource. Would doing so count as "tampering with a hostee's stuff as the host" and create a legal mess?