good excuses, you met a giraffe and had to escort it back home, you saved a policeman from a would be allergic reaction by saving him from ........, you have just discovered there is a meteor heading this way and are awaiting confirmation (that would be a good one as you can then go in and say you were wrong and discovered telescope needed cleaned as way out of it) can't think of any just now but I think find a good excuse I so far opt for potential meteor.