Last series (2010) is stupid

I really liked a number of the early series for their great stories and David Jason's unexpectedly gritty portrayal considering I'd only known him as a comedian up to then. We're only just getting the last series ( I assume 2010) in New Zealand. In this and maybe the previous series I think Jason might be confusing his role with that in the so-called comedy series 'The Royal Bodyguard' (or similar). In the preview on tv, presumably showing the highlights, there's a shot of him sitting at a computer screen looking over a young officer's shoulder and his line is "I'd like something I can sink my teeth into." Just at that moment a female officer is passing with a plate, Jason takes an American donut off the plate and says, "Ah, this will do nicely." I won't be watching.