This is from my perspective as a person working in America. I absolutely would not tell: that’s your colleague’s private business and absolutely none of the man

This is from my perspective as a person working in America. I absolutely would not tell: that’s your colleague’s private business and absolutely none of the manager’s. It also puts your colleague in a terrible position if his attempts fail. If you believe that your colleague is that critical, discuss it with him directly and discreetly, and maybe make a point of evangelizing him to the management (but do so without tipping anyone off—shouldn’t be too hard if the colleague is that critical).