What did the tree do wrong?

      Out on patrol, me driving and the boss in the turret, we discovered this page from a Chapbook, depicting Dick Turpin and Bess in full flight from their pursuers.
      Now we know that these Chapbooks were the Sky News or CNN of their day, getting the information out to the public quickly and  efficiently; news of hangings, 'orrible murders, battles won and political and royal scandals. Nothing changes does it, they were the 'red tops' of their day after all.
      The Chapbooks were then sold for very little money to a public ravenous for lurid news. Once again, nothing changes!
      The big question on this example lies in the background. Why is the nearest pursuer shooting the tree? Maybe he shot the one in the foreground too?
      Answers on a postcard to the Two Terriers as quickly as you can please.