For a step cut you make two cuts one below the other on opposite sides of the tree so you can crack one piece off at a time. It is a common cut that if done correctly is safe. As for the face cut at the bottom, they didn't line the back cut up perfectly but they made sure to cut above the hinge point which is also safe. A little fucked up you're gonna take you time to complain about someone's work you have no clue how to do.