Under what circumstances could a loan potentially be rejected after “pre-approval” or even after “full approval”?

Some examples of circumstances that might result in a loan potentially being rejected are: (a) if the customer loses
their job; (b) if the customer’s actual income and/or employment does not match what they entered into their loan
application; (c) if it turns out that the customer does not actually own the home (either directly or via a company
under their control) and the owner of the home is not willing to be a co-applicant on the loan; or (d) if the customer
or one of two co-applicants dies.