Due to various factors, forensic (RUF) type data might not currently be available to help investigate a problem that you have noticed in the aggregate (RUA) data views such as in the Data Explorer.
What about future incidents?
As long as some messages are received by Email Service Providers which provide forensic feedback, there is a chance that the views you're looking for could come in later.
To this end, we suggest you schedule a daily report for yourself, based on a specific view you create in the Failure Samples utility. If a message matching your specific search does show up, you'll receive a report on it and can proceed to the portal to investigate further.