CB Coverage..??..AWOL?

Why does my CB, who was covering the WR,suddenly decide to rush the QB,just leaving the WR completely open to score from 60 yards?
https://mfn1.myfootballnow.com/gamecenter/view/6535#1181158

It's a cover two. The CBs have the short zone. I think the SS could have played it better, but he does have only 47 zone coverage . Perhaps qb cannons 100 look off stifled the SS read as well as the wr's 100 route running sold the route perfectly . That's as good read by the qb imo . Too bad the fs with 97 zone coverage made the same poor read so idk

If a player in deep zone lets a receiver go beyond him, either it was his zone coverage skill or he bit on a play fake. That was a play action run, so it's likely the 97-rated zone safety bit on the run, the other could have just as likely been his zone skill.

Thanks for replying with the answer JDB,much appreciated.

Your doing a great job.