Just found this: looks like I was correct, slow acting insulin like Lantus might be ok, but not the fast acting mealtime insulins:
"BYETTA is not insulin and should not be taken instead of insulin. BYETTA can be used with Lantus® (insulin glargine), which is a long-acting insulin, but should not be taken with short- and/or rapid-acting insulin. BYETTA is not for people with type 1 diabetes or people with diabetic ketoacidosis."