I may not be an expert on epilepsy, but I've never heard of people engaging in complex purposeful actions during a seizure.
Anyway, the release you received means that Walmart agrees not to sue you for that particular shoplifting incident. They still have a year to file a police report, but they may choose not to. Since you haven't been charged with a crime, you have no criminal record; a civil demand is, as the name implies, a civil matter.

