How this case is different from "A PERSON" coming in front of your bike?
I speak from experience. And a Disc Brake gives you a boost in your confidence. Because You only have to lift A FINGER to initiate the brakes (as compared to THE WHOLE FOUR/FIVE in a Drum Brake), your brain will find it "easier" to react to, and will work "quicker".
Please don't be that guy ... who needs to be in such a situation to be able to "learn" from it.
Anyway ... lets not make this a debate and focus on praying for the member.