Disclaimer: I missed a lot of the first half due to, ahem, geographical issues.
I did see some clips where Oko-Flex seemed fairly positive in his contribution. But the thing that stuck in my mind was an incident in the first half where O-F and another Swans player (can't remember who) were in the right back position, trying to defend against two Wigan players. The Wigan players played around them with ease, and I thought at the time that it was too easy - clearly O-F made zero effort to carry out his defensive duties.
Now, I know he's not a defender, but that doesn't mean he doesn't have defensive duties. I don't know if that was what annoyed RM, but it certainly annoyed me.