even if it was crap food, that might have been their tea! pot noodles might be crap but it isn't going to kill them. At least the mother is feeding them.
I think it sounds like a harassed mum, who was prob stressed and wanted something instant for tea then throw them all in bed. I would sympathise, even if I would rather eat the container than the contents of a pot noodle.
Who you saw could have easily have been me. I have four kids, the oldest have just turned 6 and 4, and the twins are nearly 15 months. I leave them in the car regularly. It wasn't such a big deal a few years ago, jsut people are increasingly paranoid now.
I've popped to tescos for a pizza for tea because they've been driving me up the wall all day and I want to be able to just stick tea int he oven and be free to keep them entertained until bedtime. It is a small store, there are glass windows, and I can see the car from inside. And mine sit nicely, they don't hang out of windows.
I def do nto take them across garage forecourts or into the school to for pick ups/drop offs. I'm gone a few minutes, there is no point! They are safer in the car then outside a school.