Thelastshard

Having read the epilogue there are few things that didn't make sense at first. I have found reasoning for most but am still confused about one thing regarding the engagement between Hoid and Todium. The problem is WHEN and HOW exactly did Todium corrupt the memory. Because the conversation was still happening when Hoid was attacked(so the memory still must be in his head). If that's the case, Todium would have to wait till Hoid actually keeps that in the vessel there inorder to corrupt it which gives Hoid an opening and a loophole. If that's not the case then I can't understand how he will be having the conversation and still storing the memory in those vessels. Anything that I am missing?