As i have pointed out on several occasions. The Scottish independence referendum had a sub clause, that if there was a 'Significant change of circumstance' after the vote it would automatically trigger a 2nd referendum.
The UK leaving the EU would constitute such a 'Significant change' so it would mean another Scottish independence vote. This time the choice would be 'Stay in a non EU , UK' or leave and join the EU on our own!
Scotland would then be virtually certain to join the Eu on it's own and give England a land border with 'Europe' for the first time in history. ( or even 2 land borders as Wales would probably follow suit)