Well in my experience peoples responsibility tends to end just before the point of having to pay to replace or repair something they screwed up.
Don't take this the wrong way but there are people out in the world who echo what you have just said but it's a different story when their own stuff is involved.
The problem with what you said about responsibility is that it gives people the green light to put the absolute minimum effort into something and then use that excuse as a get out of jail free card when there is a problem.
Example:
Imaging you brought me a carb you had just purchased. You tell me to go through it and fix anything it needs. I give it a wash, check the jets , replace the power valve and gaskets. You stick it on your engine but it runs a little rough but not too bad. You take it for a drive anyway but it starts to backfire up through the carb, as you try to get home it backfires so bad that the air filter catches fire and you get some heat blisters in the paint on your bonnet. After another inspection of the carb it's found that the emulsion tubes weren't machined correctly and that was the cause of the backfire and damage. So you come back to me as your bonnet sits there still smoking and ask me why I didn't see it or fix it especially when you told me to "fix anything".
I say to you that it's a major operation to get to those sealed in emulsion tubes, also I've never seen that problem before. I then shrug my shoulders and say "hey man... where dose my responsibility end?" and promptly show you the door.
I'm sure you'd be a very happy camper after that...