Yeahhhhh, I get that. In fact the NTSB report describes what they did, but not *how* they did it. And...not being familiar with all this fly-by-wire stuff, I just wasn't sure how they could simulate a single-engine failure and "fool" the FADECs into not trying to maintain 100% NR, which is their primary task. But I guess they did.
Pretty standard way of simulating OEI these days, for both test and some operational types. Don't disagree with much of what you say though.