In my experience, BBO also adjusts the last round as usual, but not before the results have been uploaded to the results server. Like the previous poster, we also add extra time to the last round to prevent this from happening, but BBO also re-uploads the (possibly amended) results again approximately 20 minutes after the completion of the tournament, replacing the previous scores. Rather than waiting for this, we find it much easier for all tables to finish under their own steam, then the initial results are fine.