The link below helps spell it out a little more: The guy on kennel duty called back to base, so he still gets to fly. The one that didn't is still "resting" and not flying. It is all about communication.
I support them both, and completely understand their zeal. There is nothing more rewarding in a helicopter pilots life than rescue missions. Can't blame either one the least little bit.
http://www.washingtonpost.com/wp-dyn/content/article/2005/09/07/AR2005090701352.html