Legally, Brexit was more like an opinion poll. The proper response would have been to recognize the slim majority's interest in leaving, negotiate a Brexit deal

Legally, Brexit was more like an opinion poll. The proper response would have been to recognize the slim majority's interest in leaving, negotiate a Brexit deal before committing to leaving-no-matter-what, and then put that detailed deal to the voters in a legally binding referendum so they could actually know what they're voting for.