I wouldn't categorize it as selfish. Maybe slow but not selfish. If you have a Mohammad Yousuf at one end and a Abdul Razzaq at the other, should Yousuf be the one who should also be hitting out? Probably not. The sensible approach would be to let Razzaq hit out.
Haris is a good hitter of the ball so it made sense for Rizwan to hold back and let Haris do the power hitting. Also Haris wasn't really taking any risks. He was very measured and hit only those balls that were there to be hit. And he hit them in areas where there weren't fielders so it was a safe shot anyways.
I'm not a fan of Rizwan in the ODI formats as I think he'll be too slow when batting first, but today he recovered well and marshalled the chase nicely. I wouldn't be critical of him for tonight at least. He has been awful in the past 10 ODIs though.
Except Haris is closer to the yousuf type of player than Razzi.
Haris is a proper middle order batsman like yousuf.
Razzi was dispensable. And rizwan playing as a keeper is more dispensable than Haris.
But it was Haris that had to take the risks.