The Web Shield almost from its inception has had a very high degree of accuracy. That can be seen from the many topics in the viruses and worms sub-forum, with many site owners professing their site is clean only to find that it wasn’t. That said it isn’t impossible for an FP, just that they aren’t frequent.

Given the name of the site, uploading.site I wouldn’t be too surprised if there weren’t malware examples contained within.