Once again, there is no such thing as "against traffic" on a sidewalk. Sidewalk traffic is two-way. The fact that vehicle traffic on the adjacent roadway goes in one direction or the other should have no (pardon the pun) impact. You could just as easily die from walking down a sidewalk where drivers entering from a driveway fail to do what's required of them and look BOTH WAYS down the sidewalk before even checking the street traffic. Is it safer to have to cross a busy street, and later cross back, only to use a sidewalk in a way that you happen to be going the same direction as the adjacent vehicle traffic? Should you have to go an extra block if you're using a sidewalk adjacent to a street that happens to be one-way, in the opposite direction of where you're going?

Driveways are a primary (and, one would hope, obvious) reason that, in many places that allow bicycle use on a sidewalk, it's still illegal to do so where a building directly abuts the sidewalk.