It's a new transaction with new paperwork and call in. When I had my FFL i used white out a few times in my bound book, never on a 4473, no cross outs either, if the 4473 was not correct it was done over.
I never had a problem with white out in the boundbook during a compliance inspection. I also kept all of my receipts in order by date whether the gun was purchased from an individual or a distributor. During my first compliance check the compliance guy looked like he was really paying attention to the first white out mistake he came across, without him asking I produced the receipt for that firearm, it matched the information written over the white out, he stopped his inspection there. I did get hit on a few errors or more like his pet peeves, I think during a compliance inspection they HAVE to hit something.
A backround check without the purchase will get you jumped on by the BATF or whomever is doing the check, FDLE here and the locals. If the person whom you are doing the check on comes back as someone prohibited to buy a firearm they will be looking to arrest this person, this I know as a fact, at least locally.
When I had my license and someone would say they are not sure if they can buy a gun I'd tell them then they do not want to check by filling out a 4473 because if they are not permitted to own a gun they will be going to jail, I'd tell them to go to the Sheriff's Office, the SO would normally help them out.