Why the frick would he leave the girls with a stranger? The guy didn't really seem suspicious, sure, considering that we have art indications that wouldn't exist in real life. However, There's no reason for the girls to not go with him. It's not they it's impossible for them to continue what they were doing from wherever the mother went.
I mean, that's not even a matter of being suspicious of the guy. It's that you wouldn't leave the girls behind for the simple reason that you're at that place as a group and the reason he left is not a uniquely one-person job. It's not like he asked them to wait a moment while he took a dump or something.
Normal people IRL in a group in such a situation would probably have taken the shoe as a group and then gone on their merry way with splitting up not even crossing their minds because it's just so natural and more efficient to stay together for it.
And why the heck did the girls not just go with him of their own volition? It's not like he ordered them to stay.
