One thing to do is to quickly check that there is not anything truly urgent such as burst water main, then wait a day or two, and then write to thank the person for their contribution and say the matter will be considered at the next EC meeting. People like this are looking for the satisfaction of making you jump. Of course make sure you respond properly in due course to any matter that has substance but slow down a bit so you are not dancing to this owner’s tune. If their self-important ego is not being stroked as much they often go and bother someone else.
Make sure the EC can laugh about it and build some supporting solidarity there. The most destructive thing about people like this is that people who have joined the EC for the first time and might grow to make a useful contribution get put off and never come back.