I'm a "just a minute" kind of mom. As in "Stay right there I'm gonna get the camera it'll just take a minute." This can be dicey, and sometimes downright illegal. But, like all moms who don't have professional nannies - living on the edge is a way of life.
Do I take the kiddo inside where he can get into trouble while I come back and get the groceries? Or do I leave him buckled in his seat in the car where he can be stolen along with the car and take the groceries in...
I usually go with leaving him unattended in the house rather than out of it.
Then there's bad judgement based on boredom....He'll be ok while I run and get a book to read. Sadly, I can't even remember what I went to get "for just a minute." I left him throwing toys into the bathtub, which seemed safe enough. Guess not.