This TED talk discusses about new research in multirotors. New algorithms are being developed, for example, to fly quads when upto two of its rotors are damaged and for cooperative flying and doing things

any idea on the the types of fc they are using???

Of course their own FC 

Their own FC or maybe a custom firmware in an existing FC

They using external sensors and external processing units to archive better accuracy, flight controllers didn't have much role in this.

I saw this video last year, and was fascinated. This is a whole team who has designed this quad, but its really Awesome.

I saw this video last year . Awesome one . I think they are using external image sensors to maintain the quad , we can see markers on the quad , on certain angles we can even see the tracking devices placed at different angles , especially on each  corners . I think he the speaker also mention about the trackers during this session .