The two officials behind the goals have been staggeringly useless barring one incident so far.....
Are you talking about an elbow kick on Pletikosa in match against Ireland? In one of the replays you can see referee behind the goal looking in that direction and he did nothing about it. And if he shouted (they have communications equipment) that there was and elbow on Pletikosa's face that would be a direct red card I persume.
Just watch this video from 18 second on and you'll see what am I talking about
YouTube - Croatia vs Ireland Goalkeeper Elbowed