I'd probably feel more comfortable with it if his eyes were looking straight ahead but I don't think he looks goofy or derpy - I think his attitude is very much there and one eye looks like it's got a Clint Eastwood squint. Each one of the Turtles gives me a slight element of doubt about their eye positioning but I think that probably goes to show that most of them would do this.
From what I remember, they were at least in the same plain as each other, so there's that. Would be something if these had PERS.