Rosemary is 100% correct in her view that people should be encouraged to think about the data that they are using. They also need to take ownership of the data, in the sense that besides checking everything, they should then seek to add value to it by adding to the facts that relate to the individuals.
I am currently working my way through all my deaths in Utah and Arizona checking whether I have death certificates and adding to them if possible where I do not. One thing that keeps cropping up from the new certificates I find, is that what I already have is in conflict with the death certificate.
Another thing that comes out when checking deaths of females is that you cannot find them, but when you switch to using the forename and dates you find, that for whatever reason the compiler has chosen not to record a subsequent or even first marriage.