I agree that this thread can be closed and will do so now. Though it's always wise to participate in your own care, the EMG is the EMG and given the legal implications, if it could not be relied on, that would be so stated. But as Nikki pointed out, it was the NCS that was judged technically difficult.
PCPs aren't qualified to diagnose MND, or they'd be the ones doing it. You already identified one very misleading statement the PCP made, so I'd be PCP-shopping about now.
After any medical appointment, if you are confused later by any seemingly contradictory or not-sure-what-you-heard verbal statements, these can often be clarified via brief portal messaging.
Damage from high ammonia is cumulative over time, as with many toxins, so all or some CNS effects may persist even when the level dips lower. That's one reason why it's important to find the cause as the content I linked suggests.
All the best. You seem prepared to advocate for yourself, so I hope you do so based on the evidence in front of you.