Never tried it so I may be wrong, but IMO the best solution is to avoid pizzing a Hog off. If they are injured, cornered or otherwise get panicky is when they are the more dangerous.

They rarely attack unprovoked, they aren't true predators, but can be predators of opportunity. Sure there are exceptions. The vast majority of the time their instinct is to flee. The exceptions are usually predictable, like you are standing between them and escape (which may be just the direction they are pointed) or the Sows are protecting their young. Or you are between them and cover or the sounder (they are herd animals). Or they are injured. Or the big one most everybody forgets, your girlfriend smells ripe and ready and Boars tend to fight for mating rights (it happens).

My best guess is they are going to panic and they tend to take off in the direction they are pointed. Few people talk about getting trampled, which may be a likely scenario if you spray one while it is facing you. What I'm trying to emphasize is, that unlike Deer that run away, as often as not Hogs just put it in overdrive and continue in the direction they are pointed or maybe an oblique and aren't prone to switching ends or directions (much) to flee. They'd just as soon run over you as around or away from you.

Why don't you try it and see what happens. I usually look for a solid object to put between me and a panicky hog, trees are your friend.