Chiglet and Spotter:
The difference is that in Antiguas case had he gone around he would have had sufficient fuel to carry out a go-around and landing but this would be the final reserve fuel being burned. Hence he would be landing with less fuel than final reserve and an emergency would have to be declared on the go-around. This is legal and i.a.w. company CAA-approved fuel policy. Its one shot then an emergency.
In the case of the far eastern airline they were making an approach with significantly less fuel, so little in fact that flying a go-around to an expeditious landing would not even be possible. Its one shot then bust.
One of these scenarios is very uncomfortable, the other is downright reckless. That is why only one was reprimanded.