A crime was being committed. The Uber driver was part of this crime. The Uber driver came for the package. When told of the crime she was helping commit, the Uber driver attempted to flee, instead of staying to report the crime.There was no demand. Walking up and saying "I am here to pick up the package" is not a demand. All the old man had to do was say "there is no package' and the driver would have left.
If a Door Dash driver brings food to the wrong house, it is ok to kill them also?
Good thing she was not committing a felony. No matter how many times you repeat this lie, it will still be a lie and your 81 year old hero will die in prison where he belongs.
If a Door Dash driver? Let us put that in proper context, as in this case a crime is being committed. So your question becomes if a Door Dash driver comes to your house to deliver food laced in poison and then refuses to cooperate, do I have a right to protect myself from this crime and do a citizens arrest?
The answer is yes. In your scenario, we must prevent the victims from being poisoned.