At first glance in the clip you showed it did look like RDM, you shot someone in the head for what seems no reason. I'm with Pie, I don't think it is abuse - just a mistake as he said. I can see why you are annoyed as it was multiple mistakes which he would have learnt from I am sure! Agree he should have used a sit but he is still relatively new to staffing as a whole (this being his 2nd week EVER) and mistakes can happen and he could have forgotten.

I don't see any major action being needed here, mistakes happen and we learn from them. Just a speaking to would be fine imo.