Dave looks like a hero in Britain, but this whole thing must look very odd from the outside.
Unregulated finance and banking throws Europe into crisis, throws one of the most important currencies in history of the planet off balance and half of Europe is near financial collapse. The nations gather in one place to establish ways of regulating this whole finance malarky. If we stand together, they argue, no one can lose. Don't worry, financiers will not move anywhere and the capital will not flee, as we will all have the same regulations.
And then Dave stands up as says "foxtrot you all, all 23 of you are wrong, I know better. We love our crooks, so unless you can guarantee me that UK will remain unregulated safe haven for the a-holes that brought most of you to your knees, you can kiss the back of bottom half of my armani suit." He then jumps on the plane and leaves them all with jaws to the floor and mouths open.
The whole cheerful and mostly fictional anecdote above aside, the whole thing must look like one crazy monopoly game to those countries that face being Albania over night if things go wrong?