"Osborn stated the fact that Article 50 could only be triggered by the UK – not the EU."
This is correct
However if there is too much foot-dragging the EU can fire up article 7 and eject the UK anyway.
Given the huge number of concessions that the UK had, what happened with the most recent round of UK demands was Cameron getting given enough rope to hang himself - which he promptly did.
The UK _might_ be allowed to stay - but you can guarantee that most of the concessions won't be retained in such an event.