Following a Broadcast on the TV Station the Night Before

Following a broadcast on the TV station the night before about a particular city councillor having been pulled over for drunk driving,Joe,a political cartoonist,drew a cartoon of the councillor,obviously drunk and with his clothes in disarray,having difficulty walking a straight line on the road with a sober police officer looking on.This was published the next day in the paper for which Joe works.The city councillor involved had had disagreements with Joe in the past and disliked him intensely.It turned out that the story published on TV was an error,but the city councillor chose not to sue the TV reporter and the station; rather,he sued Joe for defamation.What would Joe's best defence be? Indicate the likely outcome.