I think this is fair. Smalling was well positioned for the original ball, the deflection completely wrong footed him. Evans couldnt afford to risk leaving it I think, its just one of those things.
If I remember properly, I think that the ball was falling so that the opponents player would have got there first and Smalling actually wanted to defend that so actually Evans had to try to get the ball and didn't get to it properly, so he made it worse, but I wouldn't blame anyone to much.
I would say that the whole defense made a mistake, but also no one made one (could compare it to my profession - I am a medical doctor and sometimes the diagnosis is wrong, because you have to wait for results of the tests 2-3 days to be ready and in the meantime you have to treat the patient according to the symptoms and "percentages" and sometimes you are just wrong, but you can't really be blamed for it).
Now about the ball playing problem. We do have problems there, but it has a lot to do with the midfield. Look at all other teams who play with lots of passing, the midfield is running the show and they don't, like in our case, 3 of 4 balls play back to the defenders. They usually don't play with 2 strikers because then they loose the numbers, which they need to keep the ball. Look at Pep, he even tried to play with only 3 defenders (the WBs were more wingers and not FBs), or he decided to play midfielders at the back, to have a better control, as it is very hard to find a very good ball playing defender, or plays with a false nine.....
What do we have? 2 strikers, a forward as a midfielder and ACM, di Maria who is very direct, Fellaini who just can't play as a proper CM as he doesn't know how, his movement is really bad, while Blind and Herrera missed a lot of games, Carrick is 33 and can't play to many games, Fletcher just lost it all.... So, we usually have ONE proper midfielder and we play with only 3 midfielders (2 of them aren't really CMs) so instead to increase the numbers to be able to compensate their technical flaws, we actually decrease the number of midfielders and make it even harder.
So how do we expect that our defenders lead the game, especially in this formation.