Yes trust has everything to do with it. By cosigning you are retaining ALL responsibility in the event the loanee hops on a plane to a remote destination with all the money and a few broads with no intention to ever return.
Or even in the event the loanee doesn't pay it back.
I've heard a LOT of stories about people who decided to be nice a cosign a loan for a friend. Friend cant make payments, or just simply doesn't. And boom. Bank goes to YOU and only YOU and legally you are responsible. It can be a financially disastrous situation.