Back stabbed outlets
A sloppy job, but you're overthinking it.
Having been cut, no current is flowing through the backstab, so no heating, no arcing, no problem other than if you handle the outlet while the circuit breaker is on and fail to respect the short stubby live wires poking out the back. Since it's generally inadvisable to play with receptacles out of their box with the circuit breaker on, not usually a problem.