A kidney transplant incision wouldn't be in the front abdomen; it would be behind the lateral obliques on the rear sides.
As a medic, T.J. appears to show a disregard for patient safety. While operating and while sterilizing her instruments, she and those assisting her neglect to wear masks to prevent infections that she has little to no ability to treat. However, given their situation, they do lack the proper supplies so have to make do with whatever they have.
When T.J. is preparing to take a blood sample from Greer, he rolls up the sleeve of his T-shirt. This is pointless: blood is usually drawn from a vein in the crook of the elbow, confirmed by T.J. putting a rubber tourniquet around his upper arm.