That's exactly what it means, Triple - that they are refusing to be honest.
Crash course in the "fog" is that this is standard, especially at the first.
All that fun dopamine and adrenaline that amps them up during the affair/bad behavior/whatever also makes their cognitive function go bye-bye. Yes, even science tells us they get stupid. Profoundly, tragically, destructively stupid.
If I never see the blank/confused look my husband got during the first three weeks post DD again, it still will never balance out. Yuck, yuck, yuck.