Yes, they did mention no direct eye contact.

Here's been my general understanding based on various readings: with a charging black bear (in the absence of readily available bear spray) you don't move during the charge or shortly afterwards; whether or not you avoid eye contact depends on whether it's a mom defending cubs ("No mom, I'm not a threat, not even looking you in the eye, it's just little old me") or more of an aggressive challenge ("I'm a tough dude, not questioning your authority but you don't want to pick a fight with me regardless, Mr. Bear") or a stalking bear (fight back any way you can).

But of course it depends on the "authority". Doug Peacock, an author who wrote about spending a lot of time around grizzlies and has apparently had bazillions of encounters, wrote about acting more assertively with grizzlies only when it's a young male acting out his testosterone, but otherwise as you say being soft spoken and non-aggressive. I'm not recommending that but it's interesting to note.

The one universal thing seems to be not to turn around and walk or run away after a charge; that signals that you are "prey".

And yeah, I think my reaction to a charge would be soiling my pants, regardless of charging species. So far I've had plenty of black bear encounters but no really close-up ones.