Fredo was naive but I don't know if he was THAT naive.

His outburst in the boathouse comes from a lot of deep seeded anger. I think Fredo may have told himself it wasn't going to be a hit, knowing that it was. I think the most logical explanation for whoever opened the drapes is that it was Fredo.

And the connection between Fredo and Ola was pretty good if they'd already been to the Superman show in Havanna before.