OT- Curling strategy question

Watching GBR v US... in the 6th end, UK up 3-1. UK knocked out all stones on their final throw and US had the hammer. On the US throw with the entire ice clear, the curler proceeded to throw a stone that he seemed to not even care about getting a point on and it sailed right by, bypassing to me what seemed to be an easy point opportunity. The announcers didn't make a big deal of it either. US ended up losing 3-2, so I think that point they left would have made the difference. Am I missing some intricate curling strategy / etiquite here?