I remember seeing that as well, but assuming we're remembering the same picture, I don't think it was an olive (Liasis olivaceus), plus olives get pretty hefty as adults (can be over 4 meters long, or roughly 13-14 feet). I think I remember the snake in that person's pic being a brown water python (Liasis fuscus), which has a much smaller adult size (more like 6-7 feet), and is darker in coloration than an olive, albeit not quite black.
Same genus, though, so you weren't too far off.