Insulin resistance on a ketogenic diet?

Is it possible to get insulin resistance on a ketogenic diet? Not likely.

Why? Because by definition, IR is hyperinsulinemia. If a person is truly ketogenic (less than 20 g carbs/day), the chances of the person to be hyperinsulinemia is unlikely.
So, what is going on? This person has acute glucose intolerance. It's almost like the body's stuck in fat burning mode. This person lacks preformed insulin in their beta cells.
Beta cells like to be ready to go at all times in the event someone eats carbs. But a person who has been keto for a long time may not have a production of preformed insulin for the 1st phase insulin release. They must wait for the beta cells to produce the 2nd phase insulin.

As a reminder, insulin resistance only occurs with high insulin. A ketogenic diet has low insulin.