Well in all honesty, this was not a "honest mistake". From the description, this sounds like operator error or lack of knowledge in the equipment. And the positive outcome was not the result of his mistake. The patient recovered despite his mistake
I mean let's be honest, we continue to demand higher educational standards for EMTs and paramedics, yet a paramedic shocks a cardiac arrest while the monitor is not reading a rhythm due to operator error and we say, "everybody makes a mistake"?
Do I think the guy should lose his cert? No. He mentioned that he had remediation and retraining, and I think that's probably enough. I'm sure he feels bad enough already. But it's certainly not an excusable mistake with, "oh well, things happen."