If this is something you are selling and that wetting with water and burnishing won't fix, then either reduce the price with the customer's approval or start over; if it is something for yourself then don't worry about it. Customers pay for the quality of your leather work so it's up to you what you want that quality to be. When I am making an item for a customer that I make a mistake on I usually just start over and give the one with the mistake to the customer for free.