Reminds me of a scene in Ironman... heh.
A Heat seeking missile should be able to shoot it down no
problem. If the Su-27 can shoot down a Hermes450 with a Heat
seeker, this should be no issue.
The Su-27 was lucky in being able to shoot down the Georgian
Hermes-450 prop-driven UAV, which probably had the
UAV handler unaware of being tracked and a missile coming up
its tail.
The same Su-27 may not be as lucky trying to hit this
'Fusion Man' who is also a Swiss Air Force fighter pilot
and more familiar with aerial combat than the UAV
operator who got his Hermes 450 UAV shot down.
With courtesy from YouTube, the video of the 'Fusion
Man' in flight had shown the ability of the 'Fusion Man' to
pull quite a few tight turns, which may allow him to probably
lead the missiles back into the tail pipe of the Su-27.