From California Fish and Game web site:
"Until the mid 1950's, wild pigs were unclassified under state law and could be killed with no restrictions. In 1957, wild pigs were designated a game mammal by the State Legislature. The Fish and Game Commission soon established hunting seasons, bag and possession limits, method of take and the conditions for using dogs. In 1992 Fish and Game Code Sections 4650 through 4657 were added that required hunters to possess wild pig license tags while hunting pigs."
Hunters described in the TV show may have been in violation of fish and game laws.