A bit of background helps for this:

My cat is elderly and remains indoors most of the time, in the kitchen. She has a litter tray and everything else she needs to get by in there with her. Recently theres been this tom thats come in and sprayed its stench all over the kitchen on frequent occasion. Anyway, I went out this afternoon, and left a big, hefty box blocking the catflap so said offending tom would not come in. Anyway, I come back, and lo and behold my cat is outside (and wants to be let in due to the box STILL blocking the door) AND the kitchen smells of cat spaff.

There can only be 3 solutions:

1) a cat/ dryer exhaust interface has occured. This has happened before, though not with the same cat.
2) The cat has somehow moved the box, let in the tom for some kind of sprayfest, and then moved it back blocking itself out.
3)Cats can teleport.

I favour the 3rd option, though the implications are massive.