I thought that was overly complicated a question.
If someone works for a bank as a teller, and they are called in on a Saturday morning with a 9am call because another teller is sick, and they were up until 4 at a party drinking, and they take a quick shower, hop in their car, and while driving to the bank run a stop sign and run into a day-care bus and kill a half-dozen kids, is the bank liable?
Should the bank have known that the person was likely to be partying on a friday night when not scheduled for work? Should they have asked? The person probably has minimal insurance, but can we go after the national bank that owns the branch for millions of dollars?
I don’t think this is equivalent either, since the truck driver is paid to actually drive a truck, and wasn’t just commuting to work.
A semi driver employed by WalMart, on the clock for WalMart, driving a semi for WalMart, is acting with the scope of his duties as an employee of WalMart.