One is specified for Vf=0.7V, the other presumably for Vf=0.
Extrapolate figures 11.4 and 11.9 to see what's likely to happen at Vf=0.7V.
Friendly reminder to always look at test conditions, including those "unless stated otherwise" at the top. These really define what the spec means in practice, not just the spec's name.
That being said, I think in most optocoupler datasheets "dark current" will be the exact thing you are looking for.