I can answer that actually.
The system in place, LWScanner, is programmed, owned, and operated by yours truly, Livewire. Me.
The way the system is coded, I can only scan the files at the time of their execution, NOT their upload. The other scanner we have didn't match this to a known proxy filter at the time. The problem arose when this file was accessed; it turned up in one of the hit-logs I use to determine what is currently being executed on the server, and was queued for a personal scan of mine to determine if it fit one of the many suspension filters I currently have programmed.
Yours matched, and was then queued for instant suspension at the earliest opportunity, which was approximately 3 seconds after the match was found as no one else was queued by the app for suspension.
I apologize for any confusion regarding why it didn't instant-suspend you the moment the file was uploaded, however I cannot apologize for it actually catching you breaking the terms of service.