Library question, coded for the unread

Something that occurred to me t'other day. By the start of book 1 Coppelia has figured out that Kai is a spoiler. At the end of book 2, she seems to know precisely which spoiler he is. When did she find that out, and whose head rolled when she did? Some keen junior librarian-- 'well he'd found out too much about us and he had no family and he's bright enough so I recruited him'? Or was it (also) someone senior who approved the recruitment? Because the ramifications of 'oh right, no family you said, just spoiler spoiler spoiler, and now what do we do?' would seem pretty major. Unless the Library recruited him knowing exactly who he was, which seems a touch unwise?