its not the end of the world and the more u beat urself up about it the longer the guilty feelings will last - forget about it and carry it on like it never happened we are only human and it happens xx
... unlikely to knock you out of ketosis, ok? You probably consumed fewer than 5g of carb - that's less than there is in a CD shake. So as long as you don't go and eat the leftovers now, you'll be fine.
if it does knock you outit wont be for long drink a little extra water to flush it out, i dont think it will have done any harm apart from make cravings a bit more stronger for a day or so, dont beat yourself up about it we're all human xx