Feels like it was some big complicated thing and he had a plan about how much for each car then the pump attendant got confused.
Still no good reason to behave like that.
Indeed. Regardless of what happened he did go a little over the top. But there is more to this than only R300/R500 story and whats 'caught' on video. People don't just snap and react like this over 'nothing' (not trying to excuse his behaviour)