And invariably, people might ask: Why didn't Richard just login to his own email account when he used the bus driver's phone?
How many people would be able to do this? I wouldn't.
For one thing, I have no clue what my password is. I'd have to download and install LastPass to get my password, and I'm not sure the bus driver would be cool with me installing software on his phone.
Beyond that, I use two-step verification. So even if I had my password, I wouldn't be able to log in on a new phone without a newly generated verification code that I'd be able to get only from my current phone whose battery is drained.