Do alcoholics score lower on alcotest/breathalyser?

Although I never get shitfaced, I enjoy some drinks pretty much every night.. today I had 5 shots of vodka mixed with orange juice from 6 to 8pm, ate at 8pm, and then drank 1l of beer from 10 to 12 or so. Police stopped me at 12:15 and the test showed 0,22. Didn’t even get a ticket as the limit is 0,3. I’m a 72kg male in shape. According to every source online I checked I should have lost my license consuming that much. Did I score so low because the breathalyser could have malfunctioned or is it a factor that my body is exposed to alcohol on a daily basis?