Well, the object of shopping is to look for the items you will buy and purchase them. It isn't hard to let your child stand and look at something, or play with a toy while you scan the shelves or flip through a clothes rack while glancing over at your child every few seconds or so.
You, and your mother, are assuming that the child was physically out of her sight, instead of considering that she simply wasn't looking at the child every moment.
You cannot assume that from the article. If my child is standing next to me and my head is turned, I may very well HEAR a problem before seeing it.
It also isn't hard to just keep them in a cart. They can still play in the basket if they just can't fit in the seat.
You, and your mother, are assuming that the child was physically out of her sight, instead of considering that she simply wasn't looking at the child every moment.
If she wasn't looking, there were moments when he was out of sight. It would've simply been easier & less tragic if she had just kept him by her through some measure. Even if my mother wasn't looking right at me, she had a hold of me.
If my child is standing next to me and my head is turned, I may very well HEAR a problem before seeing it.
If they're standing next to you, they're not five feet away & unreachable when it counts.