Not another cat glitch

My kitty is living next door in a nice screened in porch area. Her official home is the porch of a neighbor's house where her litter box, food and water are. She's allowed to come inside the house but only if someone is with her.

This is because right now there is no kitty door and no way for her to get back outside to her litter box without a human to open the door for her.

Today when I was about to leave the house and the neighbor was going to get in the shower we put the cat outside on the porch and locked the door.

We looked through the window, both of us saw her on the porch.

I said, "I'm going to go home, I'll come back after you shower"

Then suddenly the cat walked out of the kitchen back into the living room.

There was no way she could get from the porch to the kitchen. No kitty door, no other open door or window anywhere. Both of us had witnessed locking her out of the house, there's no way for her to have gotten back in.

She curled back up on a chair and went to sleep like nothing happened.