Triangulate and Contour...yellow triangle

When I plot the triangles during the Triangulate and Contour
routine(using 3D faces as selected objects), I get a yellow triangle
every once in awhile. Does this represent anything?
AutoCad Map2000i /SurvCad XML2 Build 041020
routine(using 3D faces as selected objects), I get a yellow triangle
every once in awhile. Does this represent anything?
AutoCad Map2000i /SurvCad XML2 Build 041020