The answer is Yes or No, Depending on the situation.
There is a condition called Stress hyperglycemia is when there will be a transient elevation of blood sugar levels secondary to raised cortisol levels in the blood due to stress. But in his case, it's highly unlikely because for HbA1c levels to reach 11 it takes at least three months of uncontrolled sugars. Indicating a long duration of uncontrolled sugars rather than transient stress hyperglycemia.