Series 9 Episode 4 discussion

[Sir Harry]

Talking of errors....I watched this episode for the four time today (I enjoyed it that much!) and noticed a little 'slip' in the first HS and Harry scene. Has anyone else noticed that when the HS is at his desk with his coffee talking about "if you roll over you sometimes get your tummy tickled", he very clearly takes his glasses off and puts them onto his table. Cut to a shot of Harry and then straight back to the HS and amazingly he is wearing his glasses again announcing "I don't think they have put the hazlenut syrup in". Even more strangely, the shot goes to Harry who stands up and replies "Home Secretary", cue shot of the HS and alas, no glasses now!!

Normally I don't notice things but I am sure this happens. What do you think guys?