I just had to smile at most of these threads! Our yorkie seems to be a combination of all of them!!!
She is trained go toilet outside & also is trained to use newspaper indoors.
Most days she does well (sort of 9/10). But whenever she feels that we have not given her enough attention, she will pee & poop on our carpet - preferably in front of us, to prove her point.
A while ago she was quite ill with a tummy bug which lasted for 2 weeks. Amazingly she only messed in the house once. She asked to go out every time (which was just about every 15 - 20 minutes).
So I wonder why she cannot do the same now!!??!?!