Teams were not given a chance to chase and defend the total but one team got the medal based on seed ranking. I agree, the result was based on rules but this is flawed and this specific rule should be scrapped for good. We've already seen the same rule going against Associate members a few times, despite being superior sides in the competition.
If you see score card of final then Afghanistan were 112/5 in 18.2 overs. If Afghanistan were allowed to play rest of 10 balls then they could have given a target of 120 to 125 runs, which will be quite competitive seeing the level of competition in Asian games. All I know is cruel DRS method which is known for giving mysterious results, now there is seed ranking in place of DRS.