Obviously it isn't good to take any decision when angry.
Anger makes one forget his personality and make one act irrationally,
When angry we loose control over our power of decision and we end up taking a wrong step, we mostly end in regrets
The truth is that when one is angry, it is very difficult to think or reason well, so the best thing to do is to control your anger, because saying anything or making any decisions will make one regret later on. The best thing to do when one is angry is to be silent in word and decision, because if one is unable to control their actions, it will still lead to more problems. There is nothing good about anger; this has caused many people to fall into problems from which they were never able to come out.
Not all decisions require critical thinking;
for instance, if I want to start a project or a business, I should be able to have a big though. And I should do this in the right state of mind.
But if someone comes to my family and kill 3 of my siblings, do I need to think before I will conclude to kill the person? The answer is no. Even if I know that taking the laws into my hand can land me in prison, but I might become less a human if I don't decide under the influence of anger immediately.
So, decisions taken in anger might not be good, but they could be the right decisions.
Note: Not all good decisions are right and vice versa.