Causal Stories

Alice and Zoe work for the same company. They work in different rooms and both of them sometimes need to access the central computer of the company. Unbeknownst to everybody, if two people are logged in to the central computer at the same time, an empty email is immediately sent from the central computer to a non-existent email address. In order to make sure that one person is always available to answer incoming phone calls, the company issued the following official policy: Alice is the only one permitted to log in to the central computer in the mornings, whereas Zoe is the only one permitted to log in to the central computer in the afternoons. One day, violating the official policy, Zoe logs in to the central computer at 9 am. The same day, Alice also logs in at 9 am. Immediately, an empty email is sent from the central computer to a non-existent email address.

Did Zoe cause an empty email to be sent from the central computer to a non-existent email address?