I happened upon these birds on the beach and spent about 20 minutes watching them. My best guess is that the falcon caught the grebe but then lost it before I got there. The grebe was injured and could not fly or swim very well. It almost seemed like the falcon didn't know what to do. It seemed like it didn't know how to attack prey in such an unnatural state. The falcon spent a lot of time just observing the grebe. It made about 4-5 feeble attempts to capture the it during the time I was there (I posted three separate videos). In this video, the feeble 'attack' occurs at about the 1 minute 50 second mark. The injured grebe easily evades it. I know it's pretty lame and probably not what you expected to see but it's real life stuff in nature.