"Ultimately the whole chapter boils down to NLR applies in all situations except the explicitly stated exemptions RDM, VDM, and Arma bug. If it's not one of those three things NLR applies, the handbook update was to try and clarify that."
By far the easiest way to describe NLR is what David said above... and to boil it down even further:
NLR always applies unless you were killed via RDM, VDM (not a car crash), or an Arma Bug (running through a desk, multiple examples of this.)