So based on the "Range is going hot is not an official range command. I double plug so I can't hear" you are saying that RO's aren't allowed to say anything other than the "Official Range Commands"? ever?
Range is going hot, however outdated and old, is not something that an RO is saying to the shooter. They are making the announcement to everyone else on the range so that people know to put on hearing protection, shut the hell up so the shooter can concentrate, etc.
Assuming that anything an RO says while you are about to shoot is the "MAKE READY" command because you can't hear. Seems to me that a DQ is not only in the near future but deserved.
If you can't hear then you need to verify what he said. You not hearing exactly what was said is not the RO's fault because he, god forbid, said something that isn't in our precious rulebook.