The MI5 file shown to the agents in the briefing indicates that Meynell's mother is Lenka Vesely. Czech women's names (even after marriage) almost always end in 'a' or 'ova'. The correct name should be Lenka Vesela. 'Meynell' itself is not a Czech name.
In the opening scene, Lucas North tells the Chancellor that Meynell created his first fortune by shorting airline stocks on September 11, and "as the second plane plowed into its target, Meynell made fifteen billion pounds." In fact, the American stock exchanges (NYSE, Nasdaq, and AMEX) did not open on 9/11/01 at all (and not again until 9/17/01). Trading on the London Stock Exchange was limited on 9/11/01 and it closed early, to re-open on Wednesday.