Factual error: When M and his entourage arrive at Bond's estate, their cars are surrounded by sheep. They then drive on down an unsurfaced road to Bond's house, past a pride of lions he keeps on the grounds. A series of sweeping overhead shots shows us that it is all one huge field, with no fences or the like. Those sheep aren't going to last very long.
Factual error: After the grouse shooting scene, there is a map on screen which shows the A230 crossing the England-Scotland border. The A230 is really in Kent. (00:33:30)
Answer: Given that this is a comedy, the thinking was probably "Well, we'll just blow up your retirement so you've got no choice but to come out of it."
Captain Defenestrator