If the item is purchased in good faith and there is no idea the item is stolen, then you're right. However, once the buyer becomes aware the item is stolen, or is likely stolen, then there is a legal liability. In some jurisdictions, it is an offence to do nothing if you become aware a crime is taking place - doing something could be as simple as phoning the police and informing them.
If the recipient becomes aware the item is been stolen and they attempt to discard the item - either by giving it away or unselling it, they are can be found guilty of a criminal offence.
If the OP is a third party who has a friend who 'bought' a computer and the OP is aware that computer is stolen but proceeds to assist his friend to bypass security features (such as those outlined in this thread), the OP can be found guilty of a criminal offence.
As it sits now, OP has received quite a lot of input that the computer very likely could be stolen property, and therefore OP has a responsibility to either report to the police with the potentially stolen item (and in most jurisdictions, if it's not claimed a few months after being handed in, the item becomes the property of the person who handed it in), or strongly encourage his friend to do that.
There's certainly no way the OP can say "oh...I had no idea it may have been stolen..." because there are many people in this thread advising him of just that fact.
The opinions of random posters on this forum would not give him any legal liability, but just keep posting misinformation as truth.