You're right, but there's more than one way at looking at those goals.
Stanislas had all the time in the world to pick that that one. Very little pressing.
Naismith was clean through on goal. The finish was fortuitous but he was allowed to get in one on one pretty easily.
Benteke's was a good header granted but Stek was a bit flat footed.
For the Boro goal Stek got his positioning all wrong and ended up ahead of the flight of the ball, catching it facing his own corner flag. Granted it was a foul but a cleaner leap from Negredo and it was a simple header into an empty net.
Norwich's second was a great strike but he waltzed in pretty easily and wasn't pressed so if you're giving players time and space like that you're gonna get punished, like the Stanislas goal.
The truth is somewhere inbetween the two perspectives but stats are stats.
I think what this demonstrates that the occasional goalkeeping wobble notwithstanding we've cut out the silliest errors. Now it's down to getting rid of the more complex errors, like the defensive line and the midfield not pressing together.