User blog comment:LexiLexi/Is Theon the Latest Game of Thrones Villain?/@comment-15014822-20120514221702/@comment-210608-20120515225306

I think that theory is probably correct but I suspect Theon avoided doing the dirty work. He only killed Rodrik himself because Rodrik called him a coward. I think leaving it to Dagmer to do the deed could account for the horror on his face when he sees the results of his orders.