I don't think anybody is saying AEG ordered Conrad Murray to give Michael the medication... even Paris.
What they're saying is that the contract between Conrad Murray and AEG is what led to Conrad making the decisions he did. That the AEG contract was all about making sure Michael could do the tour. That Conrad was paid to do that, not to make sure Michael was healthy regardless of the tour.
Whether it's true or not is another thing... however it's a reasonable argument. If a doctor is employed and paid on the basis of their patient having to perform then their duty of care to the actual patient is compromised.