Most likely the customer or one of his friends offered to help him "pass smog" by turning off the MIL. Won't run all monitors with the pending code and failed smog. He was acting like he didn't know. I usually say "looks like the light was turned off or battery was disconnected."
A "keep alive memory", K.A.M. diagnostic trouble code, occurred previously, but is NOT occurring NOW.
It might take several drive cycles to clear the K.A.M. code as long as the problem
does NOT occur again. OR it could trigger a DTC if the problem DOES occur again.