dumb or what?

My colleague was on the phone with his user for few hours this morning to explain about some program logic. I think he has difficulties to make the user clear about the logic coz he is still on the phone. I don't think this is my colleague's fault coz as a third party that listen to the conversation, i can understand it well. So, this must be the USER problem.

Luckily my colleague is patience enough (he is still on the phone with that user). He trys to use examples to make it clear but somehow it doesn't work! I think if i were my colleague, i'll start to vomit blood coz he is repeating the same thing for few hours! I think what he need is a big hammer to knock on the user's head (too bad, the user is too far away, or else i'll do it for him :P). If i were him, i'll just write a user manual for the user coz somebody might be good in reading but not listening. My colleague is trying very hard on expaining but i don't think it will work. bless him!