While you're shooting with a group of people, it's common for the other people (the not directors) to shout out suggestions in the spirit of creative fervor.
Sometimes, there's are the best moments captured.
You might not think so at the moment.
You might even be a bit annoyed by all the sudden "collaboration."
Roll with it.
Obviously put a cap on it when you see fit ("need to move on" "stay on schedule" etc), but give other people's spontaneous creative capital a spin.
You might like the results.
Here's a picture of me rolling with it:
Hint: Snorkel_Cam was the best footage we shot that day.