He also said “Some of the best cars in the world are made in Germany. Everyone knows that German engineering is outstanding, for sure, and that’s part of the reason why we are locating our gigafactory Europe in Germany. We are also going to create an engineering and design centre in Berlin.”
Thing is with Brexit, you have 50% wanting to leave, 50% wanting to stay and a proportional represented result being playout out by a first past the post system, yielding all sorts of chaotic stagnation. Which all gets blamed upon the initial proportional vote.
Hence if any business is asked about the UK, the whole uncertainty and chaos will come up in the subject. Just that people love to presume that was the single reason and without that things would be different. I don't see any reason or indication from Elon or Tesla to of picked the UK, even without the current climate of chaos and limbo finger pointing politics.