My parents watched the LO for a few days while DH and I went on a trip together last year. It is very difficult to get my LO to sit in the car seat (and stroller and high chair ... you get the idea). When we returned, they admitted to me that one time they drove home while she just sat on the floor of the car in the back because they could not get her in. They were only 2-3 minutes away so I guess they thought this was "ok". Why they didn't at least hold her in their lap while sitting in the back I don't know.

Have your parents or any other babysitters done anything on the irresponsible side while watching your LO?