In my experience, nobody but a surveyor and a lawn applicator knows what an acre is. Probably all the farmers know what acres are when they come in lots of 20 acres or more. Real estate salespeople seem to be clueless, and newspaper reporters are probably not much better.
I can't tell you how many times someone told me the realtor told them they had 1/2 acre when they bought their home. All 12,000 sq.ft. of it.
Since this story sounds like some legal suit over damages, you can bet somebody got out their magnifier looking for each and every stump. The property owner may have hand in hiring the contractor to do more than they should also, but I would be money that no tree service cut down 100 trees of any significance just to take out two.
After all, we do it for the money, right?