Tin, Maz,
"Ask him how often he reboots his PC due to human induced software errors or through situations that the software author didn't conceive."
Hardly a useful example. PC software is unreliable as to be otherwise would push the price up. Nobody's going to die as a result of your Powerpoint presentation going t1ts up.
"Ask him how often he reboots his FADEC/pacemaker/airbag/ABS software due to human-induced software errors." would be more useful examples. Truly reliable software tends to goes unnoticed because it never requires intervention by its operator.