Nope, I'm surprised this hasn't been updated, previously, to the correct info, as I still know of folk, in the Judge groups, using it for reference.
The shotgun was a Beretta A302 semi-auto, with a casing inspired by the Franchi SPAS12. That's straight from someone who worked on the movie and sat next to the guy who made the thing. You can take it to the bank. The guy/s who said Benelli are right.