Certainly odd, but not alarming. I am a homeshare host and on at least 2 occasions I'm pretty sure I was booked simply as a backup plan. ie, They were coming to town to meet someone and if things didn't go well, they would need my place to stay. In one case, the woman checked in and left an hour later never to return. The other woman checked in, left shortly after and then came back in the morning to shower.
And on another occasion, I had a woman who lived about an hour away who literally just checked in to shower after going to the beach and then drove home. She left me a glowing review!
Who knows? As long as nothing was missing or broken, I wouldn't worry about it!