You didn't get him arrested - he did.
You didn't escalate - it's a chuffing pizza - he did.
He needed meds because alcoholic withdrawal can cause seizures and death without medication. Why was he withdrawing - because he drinks too much - not you, that's his fault.
Withdrawal isn't fun, it's totally awful, i've been there a few times but it was always my fault that I had withdrawals, no one elses, mine.
Addicts will seek to blame anyone else for their bad behaviour/their drinking. "I only drink because you ate the pizza" or whatever, what a load of crap. I drank because it was a beautiful hot day, a cold day, because I was busy, because i was bored, because I was happy, sad, angry, frustrated. Any old excuse would do.
IF HE IS SERIOUS about detox, (do you mean rehab) then I'd wait but only if its weeks away. Detox isn't enough, it just gets the alcohol out of your system, rehab deals with the reasons you drink in the first place and how to live a happy life sober. Don't let him make promises to go that will never materialise. Rehab was the best thing I ever did by a million miles.
Many of us who spent three months there are like myself and still sober years later, others are dead, others are still drinking and using.
Rehab is an amazing opportunity, the best thing, but it's not a guarantee of sobriety.
If he's serious about rehab, (a week isn't long enough, I went for 12 weeks) then give him a chance if you wish to. But be on your guard, and plan to leave is there is a relapse.
I would also plan to leave now as he may find an excuse not to go there. Plan plan and plan a life without him and how you'll finance it, where you will live etc.