Wondering if they also lose some reporting/analytical functionality by separating it from the rest of the Customer record? If you/they want to attribute this in *any* way then it's much better suited being in the/a dimension. Although you can definitely get exceptions, my rule of thumb on this would be that it's an attribute of the grain of the transaction - ie the phone call. I could theoretically want to build a hierarchy up over it. It's the equivalent of wanting to store the 'call reason' in the fact, which I'm guessing they're not asking for, because, it's an attribute of the call and again I may want to build a hierarchy up over that.