Is it legal for a bank to open a previous account after they've sent it to collections?

My brother had a couple of NSFs about a year ago on his bank account and was unable to pay the bank the money that was due, because his wife's ex decided to quit paying his child support. The bank then closed their account and sent it to collections, who have been calling religiously since, and that was that. They now use another bank, and just got done taking my brother's wife's ex to court for not paying his child support, and was set to receive half of what he owed, which was $1500. They were told the check, which was going to be a direct deposit, would be rejected from the bank since their account was now closed, and the check would be sent to their address. However, the bank re-opened their account and used 90% of the money to cover their previous debts. My question is, is it legal for banks to re-open a previous account after it has been closed without authorization from anyone?