I've lived with my ADD husband for the past seven years. My daughter and grandson both have ADD (no biological relationship to my husband), and I've notice this phenomenon. I know we aren't supposed to generalize but I can't help it. Why can't you do anything when we ask?
Even trivial things: I was once doing dishes and the water was running. I walked into the living room and said "Will you hand me that pile of dishes on the floor?" I got the classic "in a minute." WATER WAS RUNNING. Why couldn't he have done it then, so I didn't have to go back in the kitchen and turn the water off and come back to get them? My daughter didn't leave for work when she should have and so was always late. That cost her some jobs. I swear if I told my husband the house was on fire, he'd say, let me sleep 5 more minutes.
He does say " you can't tell me what to do" but for people who live together, they do have to tell each other what to do. For example, my hearing is much more acute than his. If I hear the trash truck and say "You've got to put the trash out NOW" he'll say "give me 5 more minutes" and then he'll miss the trash. I concluded I can't change this, and it was one of the nails in the coffin of our marriage, but I'd still like to know WHY he does that.