Corvo's biggest issue isn't the constant stream of horrific decisions and turnovers, but rather the inability to skate backwards. Every other rush up the ice he's getting burnt, then has to turn around and skate alongside the opposing forward, essentially handing them an easy entry into the offensive zone (and often a scoring chance). It's so brutal to watch.
It's not his fault, though. Why someone who cannot execute basic aspects of playing defense is relied on to play 20+ minutes a game is solely the fault of Jim Rutherford. You can't really even blame Muller, given that he's already playing Pitkanen-Faulk for 25 minutes. The fact that Muller has to choose between Corvo, Harrison, McBain and Sanguinetti for a top 4 spot is a total joke.