I totally agree IO - if it were a perfect world. Unfortunately, it isn't a perfect world and as I said - he (or she) who signs last will be held responsible for the aircraft's airworthiness as a whole regardless of what has been done before. This means that, as far as you can, you ensure everything has actually been done that has said to be done.
The ultimate result of this is the threat of losing one's income due to someone else's error when the authorities come investigating. And I like my job, it saves me getting a real one....