okay so the code which returned everything isn't there
actual explanation: the API server by default returns everything. the client attempted to make a request to return "pending_deletes", but as the request was malformed, the API instead went down the default path, which returned everything. then the client deleted everything.
makes sense now
but is that explanation is even worse
because that means the code path was never tested?
or they tested it, but not with a dataset that contained prefixes not pending deletion