In most oils and lubricants surfactants are added to help the oil disperse in to the moving parts. When some paints and finishes are exposed to the oil the finish will lift off looking like it has been treated with a paint stripper. Sometimes there is no indication of the damage, the oil will penetrate the paint and when you clean it with, maybe dish wash or similar type products the surfactants that are in the cleaning agent follows the oil path and causes the paint to lift. If this is the situation, the paint will not usually lift immediately the damage is often evident after the item has dried.