No matter how skillful you are or how much you know. Whats matter is that you can see the problem and point it and if you know you can say how to deal with it.
I think a problem is a problem in the eyes of everyone, so everyone can see it, the deal is when a problem is subjective or not, and this is where you should always consider the style of the person to not make mistakes like looking a picture like this: http://www.ultimonivel.net/wp-content/u ... 64-648.jpg
And say that the head is too small.
I think that even critic the style is more useful than just saying "good job", because at least gave the opportunity to reevaluate your own style.