Wow Pat, glad you are A OK.
Sounds like a hairy "start". Your point about hands waving in the air I think is one that deserves highlighting. Something so simple can alert to those behind and really get them to broaden their sights and pick up on the danger. It's a great habit to get into and there are SOOOO many situations where it can really help to keep others safe. As racers we really need to help look out for one another out there. Again, glad you're well and recovering from your bell ringin Pat..