The spacecraft that crashed through Big Ben and then sank into the Thames was a plot by the Slitheen family to gain control of Britain's nuclear codes so that they could destroy the Earth and sell it for scrap. After they were foiled by the Doctor, UNIT and the new British government began a campaign to convince the public that it had all been a case of mass hysteria; that Big Ben was never damaged in the first place, let alone that Number 10 Downing Street was destroyed by a missile or that aliens had been in charge of the United Kingdom. (All of this can be seen in the 'Doctor Who' two-parter, "Aliens of London"/"World War Three". BTW, those titles stink, like the Slitheen themselves. I would have called them "The Gas Exchange" and "Number Ten Downing" - double meaning on that one.)
So it's pozz'ble, just pozz'ble (as Mushrat would say), that the information... information... information about the attack on Big Ben and the truth regarding Clan Slitheen is locked away in Chuck's noggin.
Now, faithful followers of "Inner Toob" and followers of the televisiologist faith may remember that 'Doctor Who' had to be relegated to an alternate TV dimension because of all of the discrepancies that clash with Toobworld in general - at least the version brought back to life by Russell T. Davies.
However, I also hold that it still exists in Earth Prime-Time, the main Toobworld - even following the same storylines, but with the necessary changes to make it jibe with "life as we view it" on other shows. (For instance, Tony Blair was murdered by the Slitheen in "Aliens of London", but that didn't happen in the real world nor in the main Toobworld. And so it would have been Blair who faced the Sycorax in "The Christmas Invasion", and not Harriet Jones.)
So Big Ben would have been attacked in both Earth Prime-Time and whichever alternate TV dimension which houses the new 'Doctor Who'. (Classic 'Doctor Who' can remain in the main Toobworld.) And until such time - if any! - when the creators of 'Chuck' decide to employ that Big Ben image, the secret of the Slitheen is tucked away in Chuck.
"Do you know what I really want?
To hear the chimes of Big Ben."