You're all missing that Jags was meant to be there and wasn't. Just completed the 'mare of a day our captain had. Very harsh to blame Bešić for his bad positioning.
It was a silly backheel to be fair, Nostradamus wouldn't have seen it coming. I fear we might be reading into the error a bit too much, it's just one of those things he'll probably never do again, and on the day it was a miniature umbrella for a sewer cocktail.