Okay, yes, Charlotte, had I put on the shoes I’d have noticed something amiss. But I just grabbed them without thinking, because stuff at the bottom of the stairs goes up and stuff at the top goes down. I’ve covered this system before:

And I was not wearing shoes, and I was going into my closet anyway as part of the clothes-changing process, so I put away the shoes because now I had shoes in my hand.

In other words, my subroutines executed properly, but they were given bad input data and failed to trap for errors.