Sometimes it is easy to criticize those who insist on a "source for every fact." However, having started to do this on a few of my lines, I have learned one thing. It has forced me to correct many things I have either transcribed or remembered incorrectly.
It may be heresy to say this, but the world won't end if your citations are not perfect. However, they should lead you or someone else back to the original.
Going back and getting the actual information right may even cause you to break down those brick walls that were accidentally created by the researcher themself. Of course, this never happens to me---just other people!