Well he may or may have not been successful - as long as you know who was tupped now (and can make sure that these girls get fed/boostered according to the "revised" timetable) and who was tupped later by regular tup (by making sure that he marks all his girls and the ones not marked by him should already be done by the wee man) and then all of his offspring get sold for meat/boy lambs ringed etc, then this slip-up should be fine. ore hassle come spring and you may have to lamb indoors if at all possible for the early ones.
You would have to estrumate the whole flock to make sure everybody got covered, not sure how expensive that would work out.