Even assuming a glancing collision is better than a broadside hit (sounds reasonable), a head-on collision is far worse. So since going for the glancing collision would increase the risk of the head-on (compared to taking the hit broadside), it might have been a better bet to go for the broadside.
I doubt that thought process actually occurred, though. If a vehicle crosses into your lane and is coming at you head-on, your instinct (if you're accustomed to driving where you drive in the right) is going to be to steer right to avoid the collision. Which can put you in a position to be broadsided, especially if you panic and spin it.
I wonder if the drunk had fixated on the victim's headlights and literally drove into him.