Not sure how close bedtime was to the pick 'n' mix. Assuming you came straight home from the flicks, I'd test and correct then - not wait till bedtime. Trouble with doing that (if there is a gap between the two) is that your BG will have been high a while, won't it?
On the assumption you have your basal 'bang-on' there's a hefty amount of sugar sitting in your blood for however long .... cos it sure ain't slow-acting carb, is it? LOL Meanwhile your basal - which is sposed to only take care of your liver your lungs and your lights (etc) will have been trying to cope alone with both which in my book means neither is getting enough insulin. It isn't intelligent enough to say, I will ignore the sweeties and just work to rule, is it? LOL
And me personally, I would like to preserve me innards as long as poss, thereby enabling me to repeat an evening with/without sweeties (popcorn is my bete noir!) at the cinema well into the future .....