Maguire can't assume that. I completely agree that Lindelof was poor in that situation. He went up like he was going for the ball alone, without having to challenge for it. When he understood that he wasn't going to be able to go high (because he was backtracking) he should probably have fallen off himself and picked up the loose ball. But Maguire nonetheless hasto assume that the ball might end up in the area behind Lindelof. He has to take out space to cover that area in that situation.
Don't disagree with the covering bit but it's 9/10ths Lindelof's fault and 1/10ths on Maguire imo.
The issue isn't that Lindelof lost this one ball, it's the regular tendency he has being passive and weak in a lot of defensive actions.
Ekeke said it above quite humourously but accurately "Maguire has probably never seen such a poor attempt at winning a header".
I was shocked and slightly disappointed that we paid such an enormous fee for Maguire but imo he has been pretty flawless. Came into the team with no pre-season, instantaneously raises the standard, took ownership of the defensive line/his own defensive work and then has to babysit a tentative centre who actually does less than him (in responsibility).
I'm willing to give Maguire a pass on this just like I give to Pogba for today's game. The criticism is correct and justified on it own but they both bring much more to the plate than needing to cover for their team mates.