There are plenty of leaf prints in coal. None in crude oil.
Much like there are no leaf prints in oil derived from hydrogenated coal.
However, if one chooses to look, evidence of the biological origins are there, the same as they are there in crude oil pumped up through a well.
Which isn't to say that if anybody wants to, they can't put their money where their mouth is and hand over said money to someone buying up leases on previously depleted oilfields, secure in the knowledge that they'll be topped up from below any day now...