Particularly when your yellow card is for one of the many offenses that fall under the rubric of "unsporting behavior" such as shirt-pulling, time-wasting or obstruction.
The traffic layer, which lights up in red, yellow and green depending on the amount of traffic, also was particularly helpful on the way back to New York.
Scrum-half Care's yellow card in the 69th minute, for a shoulder charge on Marcus Horan, was particularly galling as, at that stage, Ireland only led 11-6.