Do you mean there is an instance created for Link-Attachment though the response was not captured?

What I meant is, while making CONNECT-CMIS call, it may take sometime to place the file in the repository depending on the stream size, it the mean time if Pega server gone down, what happens is Repository is loaded with file but case is not updated with link attachment page hence there is a need to apply reconcile logic. How do we handle this?