Tense problems

"As she looked out, though, something odd occurred. For an instant, one of the nearest flares entirely disappeared from view. Before Norah could worry that it was dying out, the flare reappeared. If Norah didn't know* better, she *would assume something had passed between the flare and her location. Certainly nobody else was out here...unless of course the administrator had started to feel guilty and sent a NASA team out after them. Somehow Norah doubted it. Probably nothing, she decided. A gust of wind had momentarily killed the flame."
(from Deception Point by Dan Brown)
I'm not comfortable with the tense in the fourth sentence. I would have expected something like, "If Norah hadn't known better, she would have assumed..." I can see how "Norah thought if she didn't know better, she would assume..." is perfectly fine because the so-called sequence of tense rules don't apply to counterfactual conditionals, and wonder if the "Norah thought" part may be implicitly understood in the original. Is there any other explanation, or is it really supposed to be a reflection of her thoughts like the above?

More confusing still is the last sentence in the following:

"The men of the oasis surrounded the horsemen from the desert and within half an hour all but one of the intruders were dead. The children had been kept at the other side of a grove of palm trees, and saw nothing of what had happened. The women had remained in their tents, praying for the safekeeping of their husbands, and saw nothing of the battle, either. Were it not for the bodies there on the ground, it would have appeared to be a normal day at the oasis." (from The Alchemist by Paulo Coelho, translated by Alan R Clarke)

Shouldn't the last sentence be changed to "Had it not been for..." for tense consistency?
Any comments?
Becky