Grass

Hi all, asking a question for a friend.  They've recently cut down a few trees on their land, (made up of grass and trees) smashed up the stumps, chucked down a load of topsoil on top and scattered some seed. They are constantly hosing it but still no sign of grass coming through. Its been a week or so now. Their soil is heavy clay. Am I right in thinking they should have rotavated the soil first?