From experience elsewhere, I would say that you do need a disclaimer somewhere, there is always some misguided individual who might decided to place blame, and see if he/she could make some money from suing someone.
From: Kai Hendry <hendry@xxxxxxxxxxxxxxxx> To: list@xxxxxxxxxxxxx Sent: Friday, 4 January 2013, 2:22 Subject: Re: [LUG] disclaimer text
Crikey does one have to disclaim everything nowadays?
Just say the content (and contributions) are MIT licensed and let that be the end of it.