If the trim condition was the cause of the accident and the SIM flew the accident profile, then the SIM should have a) not got above 112 knots and b) crashed.
Old Akro, you are making the assumption that the sim is a 100% faithful replication of the real aircraft. Myself and several other posters have already pointed out to you that no simulator, of any aircraft, is that accurate - especially when flight "outside the envelope" is involved.
I suspect that, due to the large sideslip angle, the fin would have been fully stalled - thus putting the aircraft outside the envelope.
And you're also not allowing for possible differences in the physical performance of the sim pilot vs the real pilot. This has also been pointed out to you.
... the ATSB flew a real aeroplane in a disciplined test manner and recorded the force required to counteract the elevator trim at different trim settings and airspeed.
I suspect that ATSB policy may not permit them to take a real aircraft outside the envelope. To have done testing with less than full NL trim may not have had sufficient validity - particularly whilst the fin remained unstalled.