Urgent: President's Outlook crashed. Pending emails and meetings all lost...Ideas to recover?

The President uses email to organize his day by opening about a hundred messages and then marking: read/unread and responding. No joke. He and the secretary created hundreds of calendar items (meeting requests) and called me because these items were not "syncing". I walked into a land mine and when I went to restart outlook of course it crashed. When outlook came back up the items ALL resynced however the "pending" items all disappeared. The president/secretary are now holding me accountable for getting these items back. However I don't think since there were communication issues that these items EVER made it back to Exchange (and to a backup). I can try to open/repair the PST (cached mode) but am NOT confident at all that anything is still there even locally. Any ideas before I get the "pink slip". There is no way of telling them "best practice, etc." They just need the meeting entries etc. recovered: no excuses.