Every study I read measures volume over a time such number of units per week. But there is a difference between downing a bottle of wine in one hour every saturday night as opposed to a single glass every night. Perhaps a study based on peak blood alcohol level during the week rather than total consumption?
The OP study seems to have dealt with older people. Retirees, without jobs, might have many 'average' days resulting in a steady daily drinking pattern. Most of the younger drinkers I know go for extended periods without drinking (weekdays) only to get hammered come the weekend. Is this worse? Maybe multi-day dry periods give your system a rest and that is better than a daily pattern? I don't know.
It's all moot to me. I don't drink, which for a non-muslim non-mormon canadian means people often think I'm a recovering alcoholic. I'm not. I just don't like drinking. It;s not fun.