It actually wouldn't be such a simple matter to write an investigation report on himself. If it's nothing but praises, Debora would ignore it, and might even think less of his information gathering ability. So, he would need to write it to be intriguing, maybe just a little bit suspicious to be mysterious, as any competent person doesn't go around flaunting their aces, but not so much that Debora would deem him someone to be avoided. It's another question if he can keep his cool enough when it's Debora he's writing the report to.