In the context of diabetic ketoacidosis (DKA), the lab finding that would NOT be evidence of DKA is:
Negative serum ketones.
In DKA, you would expect to find elevated serum ketones due to the metabolism of fat in the absence of adequate insulin. The other findings—low serum bicarbonate level, acidosis (low arterial blood pH), and very high blood glucose level—are all consistent with DKA.