If you are going to chase a cover block forward and try to remove your opponents scored disc and you have a choice to use your disc or his do you know which one to use?
If you’re just trying to get it out, use yours so if you do hit it and it sticks, it’ll be your disc that is now the scored disc.

If you need to get it out and into the kitchen use his disc so if you miss but still get the kitchen because you are shooting kitchen speed he’ll be the one in the kitchen.