I outrightly reject the idea that the goal was keeper's fault. I have given my reason behind it and since you don't agree with it, let's agree to disagree.

Now, you said he came out in 89th minute. Did you mean 79th? Whatever it is, I don't think we have enough time and I fully support him going there:
1. First of all, you don't have enough time to score more than 1 or even two goals.
2. He is going there for corners only, not like he is completely abandoning the goal area.
3. Lett's get real, even if he abandoned the posts completely, there's no way Afgans could score more than 2-3 goals. who cares if the result is 1-0 or 3-0
4. Kiran (goalie) is the tallest player on the team and brings a significant upside to corner. He not only could be a strong scorer on high corner kick, but he will also draw some defense his way, giving the balance of man-to-man or even zone defense towards Nepali side.