[jhb50]

@chap Thanks for the tip. Actually it turns out the c (conn) 's are not required, and it failed for me because I included a v (live) when it is a file.

So the minimum command that works is:
rtmpdump.exe -r "rtmp://flash-cloud.filmon.com/demand/storage/25/410/116548" -a "demand/storage/25/410/116548" -y "mp4:116548.mp4" -p "http://www.filmon.com/vod/view/5717-0-letters-from-a-killer" -W "http://www.filmon.com/tv/modules/FilmOnTV/files/flashapp/filmon/FilmonPlayer.swf?v=48"