On a more serious note, the bang you heard was most likely a spark inside the PEM caused by the IGBTs failing or a Cap inside the PEM exploding. (electrolytic caps can be very energetic when they "detonate".) New PEM for you. (905 appears when any of the HV accesses are opened w/o shutting down the car. It also follows that a HV access sensor could have been damaged during the event.)
Disclaimer: I could be wrong.