Sally is a software engineer working on developing a safety$-$critical control system for an aerospace application. One of her tasks was to create an exception handler for the application. She considered saving the registers to the stack when an exception occurred. An experienced colleague advised against that approach due to potential drawbacks. Explain the reasons why storing registers in the stack is considered a bad idea by also giving an example of how doing so could go wrong, and suggest another approach for Sally to correctly save the registers in an exception handler.