". . . but main concern is this one random reboot."
Have you considered sunspots? (Laugh)
Seriously, though, hardware often has an expected "soft" error rate, although a very, very large probability value against it happening (unless hardware is starting to fail, or some external "thing" [e.g. yes, possibly even sunspots] increases the error probability).
I've seen Cisco devices in service for over a decade without an issue, I've seen very random reboots and/or some, but not all, features/functions of the device fail. With such problems, after a reboot, device may continue to run fine for years too.
There's also issues, including reboots, caused by some really unusual software execution path or something like a very, very, very slow memory leak.
So, one unexpected reboot might not be a real concern, but, generally, reoccurrence is.
Could the CPU issue be a root cause of reboot? Yes, although, alone, I think it unlikely.
