i went back and watched his original quote and you are right, i got it somewhat wrong, he said "If cannot finish a painting in 3 days- I write to it-incomplete." Dali said this on the 3rd day of visiting Fuchs. you can find the quote here at 24:40 on this video interview with Fuchs
also i was under the impression that Dali had Parkinson disease by late 60s early 70s and Tuna fishing might fall under "painted by Dali's assistants" who painted all his large scale awesome work in the last years.