I presume you are a Councillor of this Parish Council. I suggest you and another Councillor call for an extraordinary meeting to discuss the issue, and set an agenda for it. Decide what outcome you seek, a written warning ad apology etc or whatever you think appropriate. Suggest passing a resolution at the start to exclude the public as the Clerk's employment details etc can be deemed confidential.. As the meeting concerns the Clerk's conduct somebody else should take the minutes.