I don't lie.And that's true...infact not lieing gets me into more truble then lieing would sometimes because I'm so blunt I may say something someone doesn't want to hear-but to me that's better then lieing.
Anyway,it really depends what your view on it is,how much you can tolerate before it affects your trust for that person.
Me personally,one lie is one lie to many,it might well be something small and insignificant,but if that's the case why lie about it in the first place? No need is there?
Secoundly if someone can lie about something small,they are more likely to lie about the bigger more important things.
Trust is hard to gain and so easy to lose,and to me personally lieing is lieing,or else where do you draw the line-i guess that's where you have to decide for yourself-was this an issue which will make you secound guess him in future? can you over look it at no risk to yourself? and would you of done the same to him?
I think if he told you or left you hints though,kind of makes me say well he didn't have to come clean with you and he did-that counts for something but you need to weigh it up with what he lied about in the first place.