The Case of the Runaway Shopping Cart

The case of the runaway shopping cart has yet to be solved, but its path of destruction still lingers upon my foot. The facts are listed below. Nancy Drew, can you figure out what happened?
-6:00 p.m. Chris and I are doing a little Halloween shopping at Target.
-Chris and his 'manly muscles' are pushing the shopping cart.
-I'm leisurely strolling to the right of the shopping cart.
-Sweet Princess is chillin' in her car seat, riding in the shopping cart.
-6:13 p.m. Out of the blue, the shopping cart wheels out of control and over the top of my unsuspecting foot.
- The proof of this crazy turn of events is instantly left upon my left foot(picture is 4 days after the fact, can you imagine what it looked like when it happened...the injustice).

-6:23 p.m. Chris felt bad, I laughed (after I cried) because clearly even though Chris thought we were turning right and I did not, something or someone interfered with the wheels of that shopping cart. A stick in the aisle? A broken tile on the ground? A banana peel? A Halloween ghost you ask? We will never know. The case of the runaway shopping cart may never be solved.