I agree that the seller shouldn't have put "pro painted" in the title. But if you scroll down he explains a LOT better why it is as it is.
Here is the copy/paste:
"This was painted by an Ex-GW staff member who has been gaming for years and who has entered lots of competitions so his painting is to a high standard. This model is not finished but has been undercoated in black, then the main green colour has been added with high and low green lights. The finer details have not been added yet and that is for the buyer to do and make their own."