Could the QT production team have requested that the clock be stopped? Both to avoid any continuity issues in the edit, but also as it would be showing the wrong time when the programme went out (and some people still think it's live)
Considering the number of clocks that have appeared on Question Time with the correct recording time on them, I doubt it.
I remember when QT Extra Time was on the News Channel. Chris Eakin and guests had a little coffee table and some chairs next to the far wall in N6. It's a shame they stopped using that soft area as I thought the paper review would work well from that setup back then.