Well it was found either in your control or audit process. That means your compliance management program is working. This sounds like a training issue to be covered. And review 1002.13, 13(b) (6) - https://www.bankersonline.com/regulations/12-1002-013
6. Inadvertent notation. If a creditor inadvertently obtains the monitoring information in a dwelling-related transaction not covered by § 1002.13, the creditor may process and retain the application without violating the regulation.
A key is this being inadvertent and not showing up on a frequent basis. What's a frequent basis? Some examiners I've asked answered "more than once" while others would be more forgiving.
Mark the file to denote it was inadvertent and denote in your audits that it was an anomaly and training is being done to prevent it from happening again.