I like Aidensmom's question and I had a similar child and have another question. What if the child actually prefers the spanking over time-out?
DS used to never obey when sent to time-out. His sister would go and "do her time", he would shout no and run off. I'd chase him down, catch him, put him there. He'd leave. We'd do this several times, I'd try to hold him there, we'd take away toys as additional punishment, etc. When he was a little older and stronger I'd have to practically drag him there and I was physically worn out from the little bugger... he'd grab walls, furniture, whatever he could. I would literally end up exhausted, sometimes even bruised, from his struggling and kicking. Then I'd try just putting him in his room, but he'd keep opening the door, so I'd have to hold it shut (if and when I ever got him in there)... another physical battle. He'd lay on the floor or bed and repeatedly kick the walls or door... pictures would fall of the hallway wall. He'd be told, "Do your time-out respectfully or you are getting a spanking." His answer, "I don't care!" What it eventually boiled down to was he HATED time-outs with a passion. He is a very active child, and though he physically CAN stay in time-out, he doesn't want to. When given a choice before hand, "Which would you rather have, time-out or a spanking?" he would choose the spanking (shocked us, too!)... he knew it wouldn't last long, he knew what to expect, and he knew that though it wouldn't be pleasant he wasn't going to be beaten. He knew we love him and he knew he could trust us to administer a spanking that was fair. Of course, DS is 11 now and we no longer use spankings.
ETA: our time-outs were also 1min/year, not extreme. And yet DS wouldn't tolerate it.