I'll watch out for foreign debris. I am pretty sure that's not the cause in this instance. Losi doesn't give the builder a bunch of extra parts once the kit is together.
Who knows if it grabbed something off the track surface. We are talking about lottery odds of something crazy like that happening though.
I tried to take a picture of the burned armiture and scratches on the magnets but they turned out blurry. Murphy's Law kicked in at that point and the batteries in the camera died. I thought I'd post the pics anyway, but then I realized I can't without having them hosted elsewhere on the web.
I bet you guys have killed a motor before. Picture that in your head and that's what I took a picture of!