So my professor for organometallic chemistry described the different mechanisms for oxidative addition and in talking about the concerted mechanism he said that it had first order kinetics. I find this very odd as no step in the mechanism seems to involve a single reactant, so it doesn't seem like the rate-determining step could possibly be one with only one molecule.
I have included a picture of the mechanism shown on his slides. Is he correct in saying that it is first-order? Or am I missing something?