As an expert you should be aware that security and reliability is not the same thing. Also, if you look at the full table, the bottom two providers with a lot higher outage than everybody else run FreeBSD. If you calculate an average, FreeBSD will be much worse than the other solutions. Basically you can pretty much get any result you want from this list.
Reliability in strongly connected to Security. If you need to patch, reboot, or manage an intrusion then your reliability goes down. It also means that there is less security maintenance (even though freebsd update process is more obscure).
The table show us that if you want to be the most reliable, you need to choose unix.
Or you can count privilege escalation: 61 bugs in the last 7 years for linux, 3 for freebsd.
Or you can count vulnerabilities, even thought being freebsd smaller, this is a biased comparison.
Or you can do very rough estimation:
Google "Hacked by"+ linux: 2.3 millions results
Google "Hacked by"+ Freebsd: 230.000 results (one fold less!!!)
Anyhow let's put this way: My opinion is that FreeBSD is the most secure, reliable and scalable OS. You think that Linux is more secure than FreeBSD.
Would help the community with more/different OS builds out there.