I made this recipe several months ago and had a little to high og as well ... I added 1 lb of sugar during the last 15 mins of the boil... Then during fermentation as soon as the bubbling started to slow I added another lb .... Then the last 1/2 lb when the bubbling slowed again.It got all the way to 1.008. The beer came out very drinkable but a little bit of an alcohol bite.I think it could have been better with a little less sugar.... I'd listen to Jamil on that because I think too much sugar is what gave mine a little alcohol bite since I had good temp control during fermentation.
next time do a pre-boil check on your SG, then adjust the gravity for your pre-boil volume before adding the full amount of sugar to the boil.
That recipe doesn't call for dosing of the sugar does it? Brew the recipe how it was intended before making judgements