If the item that was in dispute was verified and nothing changed with it. then the drop in your score is not coming from that dispute. It is coming from something else that changed on your report. Credit scores change from day to day because your report changes from day to day. If nothing else, your accounts are aging every day but I would look over your reports cause something else is causing that drop that the dispute it sounds like.
OP, check the date of the disputed baddies. Creditors have to update the reported date and in some situations that can drop your score, espeically if it has been years since they last updated.