The characters, Ernie (Joey de Leon), Bert (Vic Sotto), Oscar (Tito Sotto) and Kermit (Herbert Bautista) were named after the Muppet/Sesame Street characters, Bert and Ernie, Oscar the Grouch and Kermit the Frog.
When Bogart was pretending to be dead at the funeral, which scared everybody for being exposed, it could possibly be predicting the death of his real life actor Palito, who died 25 years later after the film's release.