Right... the kid who can just do everything with slimes.... builds a pit-trap in a stupid place, leaves wide enough areas either side for goblins to get past... and in the middle of combat he jumps over the gobbos into the middle of them and turns his back to the cave they were coming out of.
I suspect whoever is adapting this story to manga is to blame for at least half of that stupidity.
And... pushing the goblins into the pit from behind the pit? Wouldn't that be pulling? Oh, but they're not pulling either. They're just.... poking? ...
This whole incident is just stupid.