I do advise opening a support case for this event. This is the first time I'm hearing of such an issue, so it'd be good if support can help collect extra logs and such that might help determine root cause.
If you absolutely want to skip that step, make sure to also do the following:
Be sure to grab a backup from before you perform the delete operation. It's also worth it to do a select statement (prior to deletion) to see how many entries in the database have that mac address. Delete operations that have been committed directly to the database don't leave room for root cause analysis or future recovery (direct database manipulation should be seen as a last resort - especially since deletes do not always clean out reference keys in the database).