On a compeltely different topic, here's more proof that Michael was slippin'.

Not only did Fredo bump into Johnny Ola in Beverly Hills (what was he doing in Beverly Hills anyway?) he also spent time with Ola and Roth in Havana when he learned about the Superman Show from Ola.

Why wasn't Michael keeping tabs on him? Ha already knew Fredo was a loose cannon, with his taking sides with Moe Green, with his undermining the Corleone negotiating position with Greene by banging cocktail waitresses two at a time, by his choice of a spouse and by his overall weakness and stupidity. How is it
Fredo can go to Havana with Hyman Roth and go out in public with Johnny Ola and do it without Michael not knowing? Vito kept tabs on everyone, but Michael obviously did not.