Re: He may well have known what it meant.
I've had memory cards die on me before. It happens, it might have been he forgot it, it might have just stopped working. It's worth asking if there's any check that can be done to ascertain what causing the error and at worse inform of if a non critical piece of equipment can be ignored if not functioning as expected.
Could be human error, could be something else but if it's not worth addressing immediately move on and fix when time allows.
Biting the hand that feeds IT
