My favorite Harry Harrison anecdote is almost certainly apocryphal (a fancy word for a lie) but I like it anyway, so here goes.
When Soylent Green was being made, Harrison was completely out of the loop. He was not consulted about or shown the script, did not visit the set, got no reports of any kind. But he did get invited to the premier. Now, I should mention at this point that in the novel Make Room! Make Room!, soylent is simply the combination of soy beans and lentil, two crops that are very efficient to grow in terms of land use. He arrived at the premier uneasy, and the film itself did nothing to soothe his worries about what had been made from his story.
When the film revealed that soylent green is people, the silence that followed in the movie was punctuated at the premier by Harrison's loud: "What the fuck?!"