Objects scoring in the YELLOW zone don’t count as being on the runway, and won’t cause the loss of your clear runway points.  When roof debris is in the LT BLUE zone, same thing, it won’t ruin your runway points.

Plus, to be clear, this update does not require that the ambulance (or other object) is "completely in" the Yellow zone, only that it is "scoring in the Yellow zone".

Steve Scherr

VA/DC FLL Referee Advisor