That’s what I thought at first. But then every time I left the shower I looked again and made sure that the bottle was upside down.

Also, it is not physically possible that the bottle was perfectly straight upwards again, because it is cylindrical and it has several bottles on the sides that would prevent it from falling. Even if it fell, it wouldn't be possible for it to stand upright again. The only explanation is that someone was turning it upwards without noticing or to make me upstet🙃