Yeah -- I had to prune out a duplicate way from @watmildon's conflict resolution work (had them upload the change because iD barfed when I tried to resolve it myself and I don't use JOSM).  (As a sidenote: part of the reason we're hitting snags may have to do with the fact I'm removing some of the non-bridges on the rail line as there are several places along the line where concrete box-type culvert structures were mapped as bridges instead.