Sometimes when doing complex tasks, its tempting just to clear out an entire databases's contents and buiid everything up from scratch. Sometimes through laziness, or sometimes because you cant actually get a decent reconcilliation in terms of documents.
Its bad - it leaves a deletion stub - that is, a tiny document fragment just containing that documents UNID - hanging around so when it replicates, the 'deletion' action can be pushed around. Its an extremely efficient design mechanism for replicated databases - as long as you dont routinely generate hundreds of thousands of documents, then delete them. Every 30 minutes.