I don't know if it has been discussed, I didn't know until I saw this video. But 2 drivers were saved from possible injury by the halo in the Hulbert crash as is seen in this footage... Very interesting.....
https://www.youtube.com/watch?v=msmbe3ijMXo
Also if you're interested, check out the smoke coming from Correa's car befor he hit Hulbert, it appears his front wing endplate is gone. Possibly from hitting flying debris and getting lodged up the car and keeping him from steering/braking correctly???