On the contrary he is just being insulting by spouting gibberish. There was no tantrum (save from remoaners since). Uncontrolled immigration has been an issue for ages and no one was stopping the EU allowing all and sundry with EU passports to waltz into the UK. It was clearly a mayor indication of how little we were in control of our own country, that we had a parliament who didn't care (and apparently still doesn't understand), and the need to make the change. It was not the only reason we need to get out but was a major factor.
If anyone seems to have hit the nail firmly on the head, judging by that article, it is Henry Bolton.