But he's right there will be sooooooooooo much politics and hurdles, even when you try to be reasonable.
Other EU citizens in other EU countries can *perhaps*help, it's not that protests didn't derail TTIP for example, but the UK has made itself ... unpopular.
I don't see him as having sour grapes about the EU. I heard him speak last year before the referendum. He was clear. The EU is flawed and needs reform but we must work to reform it not destroy it. That is a more positive attitude than sour grapes.
This is a very insightful article by Yanis Varoufakis, a man who has first hand experience of negotiating with the EU.
https://www.theguardian.com/politics/2017/may/03/the-six-brexit-traps-that-will-defeat-theresa-may
tl;dr May is incapable of achieving anything other than disaster and division.