Keepers make mistakes. Look at some of the recent howlers from De Gea for example. I think we've been spoiled over the years, especially with Cerny and McGovern who made very few errors. OFW got a bad rap. How many howlers that cost us goals did he make? I can only really recall the one at Killie on the stroke of half time and even then, he made a stunning save in the second half to save a point.
A common complaint fans make everywhere is that their keeper doesn't come for more crosses but a lot of the time it's the central defenders responsibility. If you think about it, a keeper tends to stand about a yard off his line. When a ball is whipped across and is, say, five yards out, that means a keeper has to make up that ground, jump and catch or punch it in a split second. Ok, he has to be on his toes and maybe read what is going to happen but even then he leaves himself open to being caught in no-mans land and then he'd definitely be the villain in the fan's eyes. Quite what OFW was expected to do with a cross that must have been close to eight feet in the air before it dipped to the back post for Taylor-Sinclair to head home, I don't know. But there wasn't a mention of the outfield player who had failed to track his run!