If you can't get the file removed from filefront, post a comment on the filefront page where your download is, letting people know about the error.

There's no need to be sorry about what's happened. This was something new and unexpected that happened. You should be a bit pleased, as you helped discover a new bug that, (hopefully), Valve will fix one day.

For the sake of clarity, this is not a bug. This is a restriction of the Source Engine. They're not fixing it, they're adding a new functionnality (embed scenes in a bsp).