I'd be really shocked if a bag was sold by Patina and they said it wasn't re-dyed but it was re-dyed.@ironic568 this is the response I just got from patina: "It's pretty normal for color to come off when you condition it with something, from my experience, but once it dries it shouldn't happen any longer. We checked with the original owner who said the bag was never refurbished. It's also obvious from feeling the leather - bags that are reconditioned do not have that original softness to it that your bag has.
Please do not hesitate to contact us with further questions."
They have a hawk eye for this kind of stuff, which is why I appreciate them, because anything re-dyed is obvious from feel, and any good seller would disclose it.
Personally, I can easily tell from photos sometimes too if a bag has been redyed or not, even if it's the same color as the original color. But you should be able to tell more readily in person - if a lambskin bag is re-dyed, it just doesn't feel the same, it ranges from stiffer to plastick-y, or just like calf instead of lamb. That's how good sellers should be able to easily tell, and, therefore disclose (I've seen them disclose when it has been). Ask them! I agree with @ironic568 that if a bag is redyed, it could start cracking or creating wedge-like lines over time, but it is because of the hardening of the leather. Does the leather feel hard?
re-conditioning is a different story... that does not affect the leather as it's not dye or coloring, but just polish... I would ask