This seems to work fine here:
Code:
$ rtmpdump -r "rtmp://72.246.103.99:1935/ondemand?_fcs_vhost=cp37307.edgefcs.net/nbcu/nbcrewind2/203b1009039c822c017431b97da2a5de_0500" -s "http://www.nbc.com/assets/video/3-0/swf/videoplayer_extension.swf" -t "rtmp://72.246.103.99:1935/ondemand?_fcs_vhost=cp37307.edgefcs.net" -a "ondemand?_fcs_vhost=cp37307.edgefcs.net" -p "http://www.nbc.com/saturday-night-live/video/episodes/?vid=1163334#vid=1163334" -f "WIN 10,0,22,87" -y "nbcu/nbcrewind2/203b1009039c822c017431b97da2a5de_0500" -o f.flv
Source:
http://pastebin.com/f563a987c