In order to answer this vital, core question, we need to clear up a few things first.

The society's use of "you're on the hook" may imply a morality or a should or a "bad". 

But, on this site, we are operating off of a true no-fault, no "make people wrong" viewing-point.

Also, the definition of responsibility we use is not the mythical "obligation" and you're irresponsible (and "bad") if you don't do it.  This implies a use of the force in using judgment of another to get them to do something - a form of attempting to control

We choose to "take" responsibility (or not).  It is not a condition thrust upon us from the pressures of society or our internal adaptation where we make ourselves wrong for not being responsible. 

Whether we take responsibility or not simply is determined by our current level of knowing/awareness.  If we don't have sufficient knowing to be able to choose to take responsibility, we are simply lacking.  The solution lies in convincing the person (or ourselves) that it would serve us better to "take" responsibility - and the only way that can be done is through learning, in order to plug the lack.  Simple, though maybe not easy.

Jane would jump all over David whenever he implied or said that he "just didn't know" and that he didn't intend to "hurt" her.  She wanted him to apologize and do penance, based on this being all his fault.  And she just accused him of trying to make excuses, though he wasn't.  And the fact that he intended only good did not cut it at all with her.  She was on the warpath and nothing would deter her, except maybe groveling and begging forgiveness. 

(Yes, David could authentically use a "modified" apology:  "I am so sorry whenever I do anything that hurts you.  I love you and I don't ever want to hurt you.  I'll try to do better, just because I love you.  So, let's see if I can better understand here what to do better..."  He, in this case, is taking responsibility for doing what is best in the future, but not flagellating himself for being "at fault", when he simply knew no better.) 

Is this just a bunch of words (linguistics), and perhaps a form of bullbleep? 

No, it is not.

There is no fault in not knowing more than you can know at the time, since that is impossible.  There is only taking the current situation and doing henceforth what is best. 
Responsibility (quoted from Responsibility, 100%?) simply means "given what has already occurred, one responds by acting to cause the highest positive effect from that point forward."

Bottomline, "no fault" does not in any way let anyone off the hook, nor is there any legitimate hook.  It does not relieve anyone of the responsibility to do whatever can be done that has a positive effect.  However, there is no "burden" or "obligation" that is real, only a choice. 

(And a person must consider the beliefs of the other person, even if they are not true and even if they are grossly judgmental or unfair, in calibrating what is the best thing to do.  Pretending as a strategy is not ruled out, if it realistically produces a better result.  And, of course, it is best to choose to learn what is needed to plug the hole of how to get along with another person - even if the person is "difficult", for the person does not know better.)      

It is essential, for your own sake besides the sake of others, that you fully understand and buy into the reality that There Is No Fault - and that there is no need to be self critical nor critical of others!  That's a huge shift, so take the time to grok it.