The only "explainable" reasons why the washing machine may have turned 180 degrees:
1) While using the machine, the load shifted and caused the machine to start thumping around. Enough rocking will often cause a washer to move on its own, usually pulling out from beside the dryer or possibly turning a bit. The power plug and the water discharge hose will often limit its mobility. I have not heard of one that can turn itself completely around, but I suppose it's not impossible.
2) Someone came into that room and intentionally turned the washer around, either to try and look at the back of the machine, or just to freak you out, wondering how it got that way.
You can explore any supernatural reasons why this may have occurred with your psychic or occultist.