Forward footwork is faster but for those who are comfortable with fighting while moving backwards, the fast speed will become a disadvantage. From my experience fighters who move forward fast can only punch because they need their legs to move forward. This gives me free openings that I can take advantage of so long as they are moving forward like the person in the picture. The guy moving backwards in the video has more options to strike than the guy moving forward.
For me moving backwards = waiting / timing opening.
If I want to escape, then I move back a few steps and then move off the centerline to force my attacking opponent to readjust. If I don't move off the centerline then it's because I'm timing my opponent and not because I'm being overpowered.
The problem with the guy in the clip is that he got into the mindset of trying to regain his own forward momentum. Flow backwards first, move off center line, and then establish forward momentum while the attacker is adjusting. But like everything else, being able to fight while going backwards takes practice. He was getting linear punches but didn't make any attempts to parry or redirect. He just covered. had he taken an angle he could have turn it into a grappling game.