You're absolutely correct. This is why I recommend vinegar. It is because it is acidic, which is the way the natural leather fibers want to be. Leather is amphoteric so when anything above the isoelectric point of leather (~5.5) comes in contact the leather acts as litmus paper and shows a mark. You need to shift the fibers back down to about 3-5 on the pH scale.
9/17/14 at 10:55am