No and yes. The liver can make ketones out of alcohol, so technically, when you drink you'll continue to produce ketones and so will remain in ketosis. The problem is ... alcohol converts more easily to ketones than fatty acids, so your liver will use the alchol first, in preference to fat. Thus, when you drink, basically your FAT burning is put on hold until all the alcohol is out of your system.
This rapid breakdown of alcohol into ketones and acetaldehyde (the intoxicating by-product) ... tends to put low carbers at risk for quicker intoxication ... especially if no other food is consumed to slow absorption.