> a networking-based error that occurred somewhere along the way, where traffic destined for me/her was switched somewhere along the lines
SSL prevents this from happening, right? If you mean that a system responsible for returning a gmail session cookie got your traffic mixed up, seems like that would have to happen at the application-layer rather than networking.
SSL simply encrypts the connection between your browser and the server. There is no telling what happens inside Google's datacenters.
For example, if you try to reach any Google IP, it will route to the nearest datacenter regardless of where you are in the world. If the datacenter doesn't have the data that it needs to respond to your request, it internally requests the data. It might have messed up there. We can't tell.
SSL prevents this from happening, right? If you mean that a system responsible for returning a gmail session cookie got your traffic mixed up, seems like that would have to happen at the application-layer rather than networking.