If they haven't tamped it thoroughly,
(knocking all the tiny air pockets out of),
the cement/fine sand/water slurry that coated the gravel,
will be prone to waterlogging in steady rain.
The next night of frost should see some freeze/thaw cracking.
That's before we consider the negligible bond strength between
cementitious and bituminous systems.
Expect the feathered edges to go with the refuse hgv.