You may have prevented it

When someone you care about ask you for your opinion you have to be honest. Sometimes it is a serious circumstance they are facing and they are looking to you for facts as you see them. You help by pointing out the facts and weighing out the consequences in their decision on how to react to it. If you are honest no matter if they take it to heart or form their own opinion and go down a path that in your opinion is wrong, you will feel good that you were honest. If you just agreed with their point of view and didn't give your honest opinion and they choose the wrong way you would honestly feel horrible because your honest opinion may have prevented it.