I'm involved in my friend becoming homeless
How are you involved in your friend's homelessness?
We got into an argument that led to him becoming homeless.
You should not harm your friends over an argument. You might be able to help him by finding him a new place to stay or helping with a deposit to make up for the fight.
I'm only responsible for 20% of it, he should take responsibility too.
It sounds like he lost his job partly because of his own actions and yours. There are plenty of other jobs out there, help him apply and look for a new jobs. Make it up to them by letting them stay with you until they get back on their feet.