You should cease injecting patients until you figure this out, IMO.
Perhaps his practice should ask RVNC for more training rather than trying to figure it out on their own. We do have to consider that it was a small sample size he reported.
Frankly, he has a duty to report this to the company so that they can investigate. They will assign an MSL - Medical Science Liaison for a meeting. He knows this. You can't just post adverse events on a message board. The company needs to investigate his practice utilization. Especially since he is a "National Account". The company needs to have and opportunity to protect themselves from this type of "negative" comments.