gobluetwo

Interesting. Slide 40 outlines the provision for MSC, which appears to be CM, in this case. However, it also states that "If MSC does not publish its provision, apply the rule of the Check-in carrier."

Slide 41 also says, "In the case of code share flights that include a point in the US, the MSC shall be the Marketing carrier."

So 2 questions.

1) Who is the marketing carrier? If it is UA, the US DoT reservation on codeshare flights would seem to apply, deeming the agent correct. If not, then...
2) Does CM publish its provision? If not, then the agent would seem to be correct, again. If CM does (and I don't know how you'd go about finding this out), then the agent would appear to be incorrect.

EDIT: This, of course, assumes the powerpoint is correct and not just a draft, and that I'm interpreting the statements correctly.