Since logging into the backdoor account produced a `#` prompt instead of `$`, it was uid 0, so the last will and testament was either in `/root` or in `/`, depending on how the non-backdoor root account was set up.

Plus, if Flynn was running those commands while logged in as "backdoor" rather than while logged in as "root", the text displayed on-screen specifically says that the backdoor account doesn't have a home directory configured so it would treat `/` as the home directory. Which would mean the computer now has a `/last_will_and_testament.txt` file. That's pretty prominent and attention-drawing. It's going to be found by anyone who investigates that computer.

I think we can assume any hacker worth his salt has a dead man trigger. I imagine that if he doesn't reset it before a given period elapses then a script imports that will and testament text file into LaTeX and emails a lovingly rendered PDF off to the local lawyer.

Given what we learn about Flynn, the will was in fact found by the only person he cared to find it.