Your friend didnt get robbed at all.
When he dropped the other guy the guy was fighting like hell not to take too much punishment.
He was throwing up kicks liek crazy and as the round ended had your friend in a triangle.
When your friend was pinned up against the cage he was doing nothing plain and simple. He wasnt fighting back and certainly wasnt trying to advance his position!
Like you said your biased but your friend gassed and got worked.