I do not know "which" ejector he is referring to, but I have seen a M77MKII in which the ejector did not line up perfectly with the cut in the bolt head, causing a hesitation in the slipping of the ejector thru the slot. This resulted in first rounds not ejecting.

A slight bevel cut on the top of the ejector and on the edges of the ejector slot in the bolt head allowed reliable slipping of the ejector blade thru the bolt head and solved the problem.