I had a Cullen WU that validated today where there were 3 results, all of which got full credit. This is an example of a different variation where the initial replication was 2, one of which was returned on time. The other overran and the WU was re-issued. Then the original(late) WU was returned shortly before the 3rd WU came back. (Not a complaint - just another, different example of how stuff can happen).
In the original posters situation, he would have still got credit if a) the residue matched, and b) he returned his result on time (or at least before the WU was cleared from the database - there's usually a couple of days leeway on this).