No. Just no.
A state adversary WILL get in should they wish to, but any exploit runs the risk of being discovered over time. This is a better outcome than simply rolling over, and may even result in the NSA (or organisation in question) deciding the risk is not worth the benefit. Even if you're gagged and forced into cooperating, having made an agency use totalitarian powers is a good outcome - it's harder to deny the nature of the "project".
Errr... no...
The UK has tough defamation laws... so much so that many choose to litigate in the UK for stuff published worldwide. Existing in that legal climate would make The Guardian very careful - I'd imagine their legal team are used to vetting stories such as this one.
As an aside - perhaps the tough libel laws are a plus for the UK media. It at least forces Murdoch to spy to get his dirt in the UK rather than simply lie as he would in the USA.
He who has but four and spends five has no need for a wallet.