I think most maids 講大話... 當場踢爆 is no actual use, except to make ourselves feel better... as 當場踢爆 won't make them not to 講大話 next time~~
After having a maid for 1.5 years, I've learnt not to ask her for the reason or whether she did anything ..... but to directly tell her "do this today" when found dirty (and if it's still dirty the next day, tell her "you forgot? do it today" again...........
Asking her for reason or 當場踢爆 is like giving her a chance to make up stupid reason / story... which make me even more upset on top of the mistakes / things she's done.... I rather save the extra air to warm my stomach.