Here is an example, if the property is in Texas, if the seller is very old disable VA, he neally not pay any property tax, but after a general buyer bought the house, the tax rate will return to normal (usually around 2.5% now). Buyer should learn tax rate from realtor, county, title company or lender (usually lender get tax certificate showing tax rate). Not from seller.
And if you can not evidence that the seller know the mistake, you may not win on court.