Are Labradors really "physically insensitive"?

When I first started this blog I went looking through all the different resources I had collected in my journey so far, books, internet articles, websites that I had book-marked. I included a excerpt from one that talks about Labrador's being "physically insensitive". I'm beginning to think that this could very well be used as a cop-out and is potentially dangerous in the wrong hands. The statement in it's entirety was the following:

The reasons that Labradors give the impression of being hard-headed is because they are physically insensitive.

My change of thought has come from being more observant of the subtle insights my dogs offer every day. In taking the time to appreciate quite time just watching them play I've noticed that even a whisper of disturbance across Nutmeg's fur sends her spinning to investigate. We have a tree that over hangs the driveway where they play. At the moment it is shedding the tiniest of yellow flowers. When they happen to land on her she notices immediately. If she has laid down for a while and one stays on her as she gets up to move she's quick to notice and turn to investigate before shaking it off.

How can this obvious keen perception be called "physically insensitive". It seems to me that something else is going on when it comes to Labradors. It is a bit more plausible to me that Labradors, not to mention any dedicated and determined dog, when given a task will go through "hell and high water" to complete the task for a well loved owner. Dogs will also offer this determination for something of their own interest, ie. a squirrel, bird, favorite ball, favorite treat, etc. In light of this I believe that our obligation is to offer something of greater reward to them.

When they are yanking and pulling at the leash about to rip our arm out of the socket - is there a word, a command, a request we can make that can turn off that impulse? Have you taken the time to condition them so completely to know that what you have is better? Can we turn the determination and dedication they focus on the squirrel back on us at our request? This I know will not be something that happens over night. And some breeds of dogs will be more challenging than others. But can it be done? Yes, I believe it can. And taking the short cut with harsher more physically painful measures is a dangerous tight rope dance that I personally don't want to walk anymore.

Update 11/17/06:
Reading through the many excellent articles on the Flying Dog Press website I came across this article "Training with the prong collar" that really help make sense of what I've discussed in this post.